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<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta>
      <journal-title-group>
        <journal-title>A. Wijekoon);
c.moreno-garcia@rgu.ac.uk (C. F. Moreno-Garcia)</journal-title>
      </journal-title-group>
    </journal-meta>
    <article-meta>
      <title-group>
        <article-title>AGREE: A Feature Attribution Aggregation Framework to Address Explainer Disagreements with Alignment Metrics</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Craig Pirie</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Nirmalie Wiratunga</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Anjana Wijekoon</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Carlos Francisco Moreno-Garcia</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Robert Gordon University</institution>
          ,
          <addr-line>Garthdee Road, Aberdeen, AB10 7GJ</addr-line>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2023</year>
      </pub-date>
      <volume>000</volume>
      <fpage>0</fpage>
      <lpage>0002</lpage>
      <abstract>
        <p>As deep learning models become increasingly complex, practitioners are relying more on post hoc explanation methods to understand the decisions of black-box learners. However, there is growing concern about the reliability of feature attribution explanations, which are key to explaining machine learning models. Studies have shown that some explainable artificial intelligence (XAI) methods are highly sensitive to noise and that explanations can vary significantly between techniques. As a result, practitioners often employ multiple methods to reach a consensus on the reliability of their models, which can lead to disagreements among explainers. Although some literature has formalised and reviewed this problem, few solutions have been proposed. In this paper, we propose a novel case-based approach to evaluating disagreement among explainers and advance AGREE - an explainer aggregation approach to resolving the disagreement problem based on explanation weights. Our approach addresses the problem of both local and global explainer disagreement by utilising information from the neighbourhood spaces of feature attribution vectors. We evaluate our approach against simpler feature overlap metrics by weighting the latent space of a k-NN predictor using consensus feature importance and observing the performance degradation. For local explanations in particular, our method captures a more precise estimate of disagreement than the baseline methods and is robust against high dimensionality. This can lead to increased trust in ML models, which is essential for their successful adoption in real-world applications.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;XAI</kwd>
        <kwd>Case Alignment</kwd>
        <kwd>AGREE</kwd>
        <kwd>Disagreement Problem</kwd>
        <kwd>Feature Attribution</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        In the preceding decade, machine learning systems have undergone significant advancements
in their eficacy, albeit their adoption has been impeded by the challenging aspect of their
interpretability. As such, Explainable AI (XAI) is fast becoming a prerequisite for the deployment
of intelligent systems — with some countries in Europe now enforcing this by law [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. This has
spurred a surge in research dedicated to improving the transparency and accountability of AI
models. Inevitably, this has spawned a number of approaches for understanding the rationale
of machine learning systems such as counter-factuals, feature attribution, and natural language
explanations (a review of which can be found in [
        <xref ref-type="bibr" rid="ref2 ref3 ref4">2, 3, 4</xref>
        ] respectively).
      </p>
      <p>
        Attribution explainers are one of the popular forms of factual explanation methods used in
XAI [
        <xref ref-type="bibr" rid="ref5 ref6">5, 6</xref>
        ]. These explainers provide an understanding of how a model arrived at its predictions,
by identifying the most influential features (attributions) or variables that led to a particular
model outcome. One example of the use of attribution explainers is in the context of a loan
application [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ]. Here, LIME attributions are used to explain why a particular applicant’s loan
was approved or rejected by highlighting the relevant factors that influenced the decision.
Alternatively for image data salience maps are often used to convey the areas that conveyed
most to the outcome [
        <xref ref-type="bibr" rid="ref8 ref9">8, 9</xref>
        ] (see Figure 1 below for an example).
      </p>
      <p>
        Factual explainers play a crucial role in gaining the trust of humans by providing transparent
and interpretable explanations for machine learning predictions [
        <xref ref-type="bibr" rid="ref10 ref11 ref12 ref3 ref6 ref9">3, 6, 9, 10, 11, 12</xref>
        ]. One of the
main challenges with factual explainers is that diferent methods often generate diferent types of
explanations, which can lead to discrepancies in the results [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ]. For example, popular explainers
such as LIME [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ], SHAP [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ], and Integrated Gradients (IG) [
        <xref ref-type="bibr" rid="ref16">16</xref>
        ] can all produce diferent
feature attributions for the same model prediction. The discrepancies between diferent factual
explainers (see example in Figure 2) can result in mistrust not only in the machine learning
prediction itself but also in the explanations provided. When the explanations provided by
diferent methods do not align, it can create confusion and skepticism among those trying to
understand the model’s decision-making process. This can be especially problematic when it
comes to high-stakes decisions, such as in healthcare or finance, where the consequences of an
incorrect prediction can be significant.
      </p>
      <p>Addressing the challenge of disagreement among attribution explainers necessitates the
development of an efective aggregation strategy that combines factual explanations from multiple
explainer methods. While consensus voting or ranking ofers some utility, it is insuficient
in capturing the complex relationships between the alternative feature attributions. As such,
research in Case-Based Reasoning (CBR) and Case Alignment emerges as a promising avenue
for uncovering these relationships, providing a neighborhood concept that can be defined in
the context of factual explainers. This paper’s primary research question centers on exploring
the ranking behaviour of factual explainers with regard to both local and global explanations
then harnessing that to measure their relationships to identify areas of consensus. We explore
how to use the alignment of neighbourhood knowledge as a means to accurately capture these
relationships. Furthermore, we assign increased confidence to explanations that exhibit a higher
degree of alignment with alternative feature attributions.</p>
      <p>Accordingly, the key contributions of the paper are:
1. Case Alignment Confidence : A novel metric for measuring the overall agreement
between an explainer against alternative explanation methods by leveraging information
from local neighbourhood spaces.
2. AGREE — AGgregation for Robust Explanations: A framework for combining the
explanations of diferent feature attribution explainers by exploiting alignment knowledge.</p>
      <p>An outline of the paper is as follows: section 2 discusses a review of the related literature;
sections 3 and 4 introduce the aggregation strategy using rank average and case alignment
confidence strategies respectively; 6 discusses the methodology for evaluating our alignment
and aggregation approach; the results are presented and discussed in section 7; and finally our
research is concluded and a discussion of future work is given in 8.</p>
    </sec>
    <sec id="sec-2">
      <title>2. Related Work</title>
      <sec id="sec-2-1">
        <title>2.1. Inherently Interpretable Models and Explainable AI (XAI)</title>
        <p>
          Inherently interpretable AI models provide clear and understandable explanations for their
decisions without relying on complex feature attribution methods. These models are transparent
and easy to interpret because they employ simple algorithms such as decision trees [
          <xref ref-type="bibr" rid="ref18">18</xref>
          ], linear
models [
          <xref ref-type="bibr" rid="ref19 ref20">19, 20</xref>
          ], or rule-based systems [
          <xref ref-type="bibr" rid="ref21">21</xref>
          ] that allow humans to understand how they arrive
at their outputs. However, there is often a trade-of between interpretability and prediction
performance. Neural networks for example often learn better-performing models but are
regarded as black-box learners as it is dificult to gain insight to understand their behaviour.
In contrast, post-hoc explanation methods operate on opaque and complex models that are
dificult to understand. Methods for post-hoc explanation difer between their access to the
model (i.e. black box or access to internals), approximation of scope (i.e. global or local), search
technique (i.e. perturbation or gradient) and presentation of explanation (i.e. feature-based
or counterfactual) [
          <xref ref-type="bibr" rid="ref13">13</xref>
          ]. For example, perturbation methods such as LIME [
          <xref ref-type="bibr" rid="ref14">14</xref>
          ], SHAP [
          <xref ref-type="bibr" rid="ref15">15</xref>
          ],
Anchors [
          <xref ref-type="bibr" rid="ref22">22</xref>
          ] and RISE [
          <xref ref-type="bibr" rid="ref23">23</xref>
          ] evaluate learners by modifying the input of a model, whether
this is pixels in an image, words in a phrase, or similar elements in other data types, and
observing the changes in the prediction [
          <xref ref-type="bibr" rid="ref12">12</xref>
          ]. A larger diference in the output would indicate
that the perturbed feature is more important. Alternatively, gradient-based local explanations
like GradCAM [
          <xref ref-type="bibr" rid="ref24">24</xref>
          ], Smoothgrad [
          <xref ref-type="bibr" rid="ref25">25</xref>
          ], Integrated Gradients [
          <xref ref-type="bibr" rid="ref16">16</xref>
          ], and Layerwise Relevance
Propagation (LRP) [
          <xref ref-type="bibr" rid="ref26">26</xref>
          ] rely on the gradient between the output probabilities and the features
from the input or embedding layer [
          <xref ref-type="bibr" rid="ref27">27</xref>
          ]. The prediction is used to backpropagate through
the network to the input or embedding layer to estimate the feature attributions [
          <xref ref-type="bibr" rid="ref28">28</xref>
          ]. Local
and global methods are distinguished by the granularity of their explanations. While global
explanations summarise the behaviour of the entire model, local explanations attempt to explain
on an instance-wise basis. Our work is interested in exploiting the information from the various
types of explanations to obtain a more robust evaluation of black-box models.
        </p>
      </sec>
      <sec id="sec-2-2">
        <title>2.2. Evaluation of Explanations and Explainer Disagreement</title>
        <p>
          Typically, XAI evaluation methods involve some form of user study, which is sensible as
explanations are generally user-centric. However, the approach is subjective and can be costly
to undertake. Objectively evaluating explanation methods remains an active research area
but various attempts have been made to quantify the efectiveness of explanations in terms of
diferent qualities such as fidelity, interpretability, sparsity, proximity, and robustness [
          <xref ref-type="bibr" rid="ref29 ref30 ref31 ref6">6, 29, 30,
31</xref>
          ]. Empirical studies have shown that post hoc explanations can be inconsistent, unfaithful or
unstable and prone to “fairwashing” [
          <xref ref-type="bibr" rid="ref13">13</xref>
          ]. Some machine learning practitioners utilise multiple
diferent post hoc explanation methods to understand their models. Albeit, the instability
of attributions poses a significant challenge — how to reach a consensus when explainers
disagree. In [
          <xref ref-type="bibr" rid="ref13">13</xref>
          ], Krishna et al. conduct a user study to understand how machine learning
practitioners resolve the problem. Astonishingly, they found that 86% of subjects either
sidestepped disagreement by choosing arbitrary heuristics such as choosing their favourite method,
or simply did not know how to resolve the dispute. Previous studies have proposed methods
to measure disagreement in feature attribution methods [
          <xref ref-type="bibr" rid="ref13 ref32">13, 32</xref>
          ] and counterfactuals [
          <xref ref-type="bibr" rid="ref33">33</xref>
          ] by
evaluating the intersection of top-K feature vectors across two explainers. Variations of these
approaches make use of auxiliary information such as sign (whether the feature had a positive or
negative impact on the output) and rank (ordinal position of the feature in the vector). However,
little work has been done to settle the disagreements in an intuitive manner. The closest work
to ours is the study conducted by Roy et al. in [
          <xref ref-type="bibr" rid="ref32">32</xref>
          ]. Their method studies the aggregated set:
 =  ∈  : (, ) = (, )
(1)
where  is a feature in the set  of top-K most important features,  is the first explainer
(LIME in their case) and  is another explainer (i.e. SHAP in their example). If both explainers
can agree on the sign of the feature it is coloured green, else it is coloured red. This is a
step towards explanation aggregation and does reduce the cognitive burden on the end-user
when interpreting disagreement. Still, it falls short of providing a method for settling disputes.
We propose an alignment-based approach to solving explainer disputes inspired by the case
alignment [
          <xref ref-type="bibr" rid="ref34">34</xref>
          ] metric. Case alignment tests the assumption that similar problems have similar
solutions in case-based reasoning applications. We posit that by forming case bases around
each explainer, local neighbourhood information can be leveraged to better inform alignment
measures across multiple explainers. Feature attribution vectors can then be weighted by the
alignment scores to generate an aggregate explanation to present to the end user.
        </p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3. Explainer Attribution Aggregation by Rank Average</title>
      <p>When given an instance and a prediction from a black-box model, a set of explanation attribution
scores  = [ ] ∈ R×  are obtained from  explainers (denoted as ) for  features. To
remove the efects of diferences in scale or magnitude that may exist between the attribution
scores generated by the explainers, the scores from each explainer are converted to ranks,
denoted by  = [ ], where:</p>
      <p>= rank( ) = |{ :  &gt;  }| + 1,  ∈ [1..]
The ranking function, rank(), is applied to each element  . It sorts and assigns ranks based on
the sorted order of the attribution scores of the explainer, and handles tied scores randomly.
The  notation denotes the attribution rank by the -th explainer for the -th feature. In this
manner, any query or case in the case base can be represented using explainer attribution ranks.</p>
      <p>The simplest way to combine explainer attributions is to average the feature ranks. The
resulting feature weights are the average row vector, obtained as follows:
Here an average rank of each feature refers to the aggregated consensus explainer attribution
for that feature, after taking into account the explanations provided by multiple explainers. The
resulting average rank vector, ¯, can be used as a set of feature weights for further analysis or
as a baseline aggregation method.</p>
      <p>¯=
1 ∑︁ 
(2)
(3)</p>
    </sec>
    <sec id="sec-4">
      <title>4. Explainer Attribution Aggregation by Confidence Weighted</title>
    </sec>
    <sec id="sec-5">
      <title>Rank Average</title>
      <p>Despite the advantages of rank-based aggregations, such as their simplicity and robustness
against outliers, these methods inherently lack the ability to discern intricate patterns and
may overlook crucial alignment relationships. This shortcoming stems from the fact that all
explainers are treated as equally important in the process of generating feature weights, which
may result in the loss of valuable information. However, if we were to weight feature attribution
ranks based on the level of confidence of each explainer, the resulting combined explanation
not only can take advantage of the strengths of multiple methods but also mitigates varying
levels of performance and reliability depending on the type of black box model and the specific
dataset.</p>
      <sec id="sec-5-1">
        <title>4.1. Rank Overlap Alignment</title>
        <p>For a given instance, attributions from multiple explainers can be evaluated by examining the
extent of agreement with respect to the overlap in their top k features. The greater the paired
overlap an explainer exhibits in relation to the others, the more confidence can be assigned to it.
For a pair of explainers,  and  given all their rank assignments,  and , a symmetrical
alignment score can be derived as follows</p>
        <p>AlignOverlap(, , ) = |topk_features(, , )|
topk_features(, , ) = { ∈ [1, ] |  ≤  and  ≤ }
(4)
Here  is a feature index and the top  feature overlap between any pair of explainers  and  is
identified by considering the set of features  such that feature  is among the top  features
for both explainers  and . We iterate over all pairs of explainers  and  with  &lt;  to find the
top  overlap for each pair. Note  refers to the rank assigned by the -th explainer to the -th
feature.</p>
      </sec>
      <sec id="sec-5-2">
        <title>4.2. Neighbourhood Alignment</title>
        <p>
          Characterising neighbourhoods in explainer attribution spaces to capture alignment provides
more fine-grained information in contrast to only comparing relative ranked positions. In
case alignment [
          <xref ref-type="bibr" rid="ref34">34</xref>
          ], the alignment of problem and solution spaces is compared based on the
distance between the Query case, , and each neighbour case, , in each space. The idea is that
the spaces are aligned when the distances between cases are similar in both. To measure the
agreement between a pair of explainers (say  and ), using this concept, we must develop a
mapping method that permits each explainer to determine the representation of the query (and
cases in the case bases) in two distinct representation spaces, much like problem and solution
spaces used in case alignment. Thereafter as in Figure 3 neighbourhoods from two distinct
spaces can be used to assess paired explainer alignment.
        </p>
        <p>In order to create a paired representation for , the ranked representation from two explainers
(such as  and ) are concatenated to form a row vector as follows:  = [︀ , ]︀ ,
where an explainer pair such as ,  can be drawn from the set of attribution explainers,
{1, 2, . . . , }. Using the paired representation of , and cases, , in the case base, we can
use the local neighborhood alignment as a metric to assess the level of agreement between the
two attribution explainer methods,  and  (as in Figure 3). Each part of the representation
can be designated as the problem space (Explainer A space) or the solution space (Explainer B
space). In Figure 3 below,  = 5 nearest neighbours, are analysed in each explainer space. An
asymmetrical alignment score can be formulated for an explainer , given another explainer
, by taking into account neighbourhood alignments as follows:</p>
        <p>CaseAlign(, , ) =
∑︀=1(1 −  (, )) · (, )
∑︀=1(1 −  (, ))
The  notation denotes a distance computation w.r.t. to the neighbours represented according
to the explainer  space. The nearest and farthest cases are also identified for normalisation
purposes. The neighbourhood distances on the explainer  space are weighted by a normalised
align distance, which is computed w.r.t. to explainer  space, as follows:
(5)
(6)
align(, ) = 1 −
 (, ) −</p>
        <p>min
max − min
The degree of agreement between explainers  and  is directly proportional to the alignment
score whereby the stronger the agreement the closer the alignment score is to a value of 1. The
Case Alignment process is described in Figure 4.</p>
      </sec>
    </sec>
    <sec id="sec-6">
      <title>5. AGREE: AGgregation for Robust Explanations</title>
      <p>To assess the alignments between a set of  explainers, we calculate all pairwise alignment scores
and then aggregate them to determine a confidence level for each explainer. This confidence
level can assist in arriving at a consensus on feature attribution weights (see Figure 5 for a
visual aid).</p>
      <p>Let  ∈ R×  be a matrix representing the pairwise alignment relationships between a set of
explainers, for a query case. An explainer confidence vector, , is derived from  , denoting the
confidence of each explainer, , where for each  ∈ {1, 2, . . . , }, the value of  is calculated
as follows:
 = {︃ 11 ∑∑︀︀= 1 (, ) if  is symmetric, (7)
2 =1 [(, ) + (, )] otherwise.</p>
      <p>Here (, ) an element of  is the pairwise alignment score between two explainer attributions
for the query, i.e. (, ) =  (,  ;  ) ∀,  ∈ {1, 2, . . . , }, where  is any of the explainer
agreement functions. As Case Align is asymmetric, both (, ) and (, ) are utilised to
obtain a symmetric value for . Whereas since the feature overlap methods are symmetric,
only (, ) needs considered in Equation 7.</p>
      <p>Next, we use the explainer confidence vector, , to influence the level of importance to be
assigned to each explainer’s recommended feature attribution ranks, to arrive at a consensus
feature attribution weight vector for the data instance as follows:</p>
      <p>() = ∑︀=1
¯ ∑︀
=1</p>
      <p>( · )
AGREE(, ) = ¯() = 1 ∑︁ ¯()
() refers to the weighted attributions obtained using the alignment function 
The notation ¯
as the basis for the confidence scores in the vector  for explainer . Note  is a row vector for
the -th explainer, and  is the confidence score of the -th explainer.</p>
      <p>Given a set of data instances,  , a global feature weight vector,  can be computed by
averaging over all of the local weight vectors and can be used to explain a model on the global
level:
¯  () =</p>
      <p>1 ∑︁ ¯()

=1</p>
    </sec>
    <sec id="sec-7">
      <title>6. Evaluation</title>
      <p>Our evaluation strategy assumes that a feature attribution method’s ability to accurately capture
the significance of features within a domain can aid in model learning by providing useful
feature-importance information. Therefore, by weighting the feature space of a k-NN by the
agreed importance of each feature we can observe the efect on prediction performance. A stable
or increased score indicates good agreement, while a dip in k-NN indicates poor agreement.</p>
      <sec id="sec-7-1">
        <title>6.1. Experimental Setup</title>
        <sec id="sec-7-1-1">
          <title>6.1.1. Datasets and AI Model</title>
          <p>
            First, a set of black-box models is trained on 8 diferent datasets from the UCI repository 1 [
            <xref ref-type="bibr" rid="ref35">35</xref>
            ]
which cover a wide range of tasks (e.g. regression and classification), domains, and data types
(such as tabular and text). We chose to use diferent variations of a neural network for each
model, as gradient-based post-hoc explanation methods are only applicable to diferentiable
models. A summary of the trained models can be found in Table 1 below.
          </p>
        </sec>
        <sec id="sec-7-1-2">
          <title>6.1.2. Explainers</title>
          <p>Five established feature attribution methods were used in the experiments to obtain a base set
of explanations for the black-box models:
1The project code is available online at https://github.com/craigybaeb/disagreement_problem.git.
(8)
(9)
(10)
Dataset
Abalone
Auto MPG</p>
          <p>IMDB</p>
          <p>Spam
Cleveland</p>
          <p>Liver
Glass
Wine</p>
          <p>
            LIME [
            <xref ref-type="bibr" rid="ref14">14</xref>
            ] is a model-agnostic feature importance explanation method that implements a
surrogate model around a data instance to estimate how each feature contributed to
the black-box model output. LIME creates a set of perturbations within the instance’s
neighbourhood and annotates them using the black-box model. This newly labeled dataset
is used to create a linear interpretable model (e.g. a weighted linear regression model).
The resulting surrogate model is interpretable and only locally faithful to the black-box
model (i.e. correctly classifies the input instance, but not all data instances outside its
immediate neighbourhood). The new interpretable model is used to classify the data
instance and an explanation of the predicted class is formed by obtaining the weights
that indicate how each feature contributed to the outcome.
          </p>
          <p>
            SHAP [
            <xref ref-type="bibr" rid="ref15">15</xref>
            ] is a model-agnostic feature relevance explainer with theoretical guarantees about
consistency and local accuracy from game theory and is based on the Shapley regression
values [
            <xref ref-type="bibr" rid="ref36">36</xref>
            ]. Shapley values are calculated by creating linear models using subsets of
features present in a case base, . More specifically, a model is trained with a subset of
features of size, ′, and another model is trained with a subset of features of size, ′ + ˆ.
Here, ′ + ˆ &lt;= , and the second model additionally includes a set of features, ˆ,
selected from the set of features that were left out in the first model. A set of such model
pairs is created for all possible feature combinations. For a given data instance that needs
to be explained, the prediction diferences of these model pairs are averaged to find the
explainable feature relevance weights. While Kernel SHAP is the vanilla implementation
of SHAP, there are multiple alternative methods to approximate Shapley values proposed
in the literature, namely Deep SHAP, BayesSHAP and TreeSHAP [
            <xref ref-type="bibr" rid="ref15 ref37 ref38">15, 37, 38</xref>
            ]. For
example, Deep SHAP combines the intuition of SHAP with Deep LIFT [
            <xref ref-type="bibr" rid="ref39">39</xref>
            ] to exploit
additional information about deep neural networks. Deep LIFT can approximate SHAP
values by assuming that the input features are independent and that the deep neural
network is linear. As a result, an approximation of SHAP values can be obtained faster
than that of other methods for deep models.
          </p>
          <p>
            Integrated Gradients is a gradient-based approach to finding feature attribution weights [
            <xref ref-type="bibr" rid="ref40">40</xref>
            ].
          </p>
          <p>
            An attribution is calculated as the sum of gradients on data points occurring at suficiently
small intervals along the straight-line path from a baseline, to the query. In practice,
a large number of perturbations is preferred because the summation of gradients is a
discrete approximation of continuous integration as discussed in [
            <xref ref-type="bibr" rid="ref40">40</xref>
            ]. We chose 50
perturbations and an all-zero instance as the baseline for all datasets when calculating
Integrated Gradients. It is duly noted that this is not favourable in all contexts as this
could lead to null attribution. However, the literature indicates that the selection of a
baseline is an open research question with no ideal solution at present [
            <xref ref-type="bibr" rid="ref41">41</xref>
            ].
MAPLE [
            <xref ref-type="bibr" rid="ref42">42</xref>
            ] is an acronym for Model Agnostic SuPervised Local Explanations and combines
the ideas of SILO [
            <xref ref-type="bibr" rid="ref43">43</xref>
            ] for local linear modeling and DStump [
            <xref ref-type="bibr" rid="ref44">44</xref>
            ] for feature selection.
It centers around the use of a random forest which allows it to be used as an inherently
interpretable predictor or as a standalone black-box explainer. SILO defines a local
neighborhood by assigning a weight to each training point depending on how frequently
that point exists in the same leaf node as the given point across all trees in the random
forest. To obtain feature importances, it uses the same approach as DStump which works
by summing the impurity reductions of each root node in a tree where a split was made,
adjusting for the number of points in the node then averaging over the forest.
          </p>
        </sec>
        <sec id="sec-7-1-3">
          <title>6.1.3. Alignment Measures</title>
          <p>
            We compare our Case Alignment Score (Section 4) with a simple mean of feature rankings (AVG)
and the 6 feature agreement methods proposed in [
            <xref ref-type="bibr" rid="ref13">13</xref>
            ]: FA = Feature Agreement; SA = Sign
Agreement; RA = Rank Agreement; SRA = Signed Rank Agreement; RC = Rank Correlation;
and PRA = Pairwise Rank Alignment.
          </p>
          <p>The agreement of both local and global explanations is compared. We test AGREE using
global explanations to measure its ability to capture the global feature importance of the model
(Equation 8). Whereas we evaluate local explanations to scrutinise the aggregation strategy on
a more granular level (Equation 9).</p>
        </sec>
        <sec id="sec-7-1-4">
          <title>6.1.4. k-NN Variants</title>
          <p>The explanations gathered are then used to weigh the k-NN feature space using a weighted
Euclidean distance function, such that a k-NN may be represented by k-NN( ¯()).  is either
an aggregate explanation using case alignment, mean importance, or any of the feature overlap
methods, an individual base explainer or simply a function returning a vector of length 
where each element = 1 for an unweighted k-NN. The non-weighted k-NN is used as a baseline
and  neighbours is set to 5 for all 14 experiments.</p>
          <p>Given the weights from an aggregate explanation (either global or local) we calculate weighted
Euclidean distances between two cases  and  as in Equation 11:</p>
          <p>⎯⎸ 
(, ) = ⎷⎸∑︁ ¯()( − )2
=1
(11)</p>
          <p>Mean Squared Error (MSE) is used to quantify the performance of the aggregate explanations
for regression datasets, whereas accuracy is used to evaluate classification explanations.</p>
        </sec>
      </sec>
    </sec>
    <sec id="sec-8">
      <title>7. Results</title>
      <sec id="sec-8-1">
        <title>7.1. Explanation Fidelity</title>
        <p>The results of the global explanation experiments (shown in Table 2) suggest that the AGREE
method using any of the feature overlap methods performs equally as well in terms of fidelity
(faithfulness of the explanation to the model) as taking a simple average of feature rankings.
AGREE based on case alignment falls short by one dataset. The closeness in results could suggest
that the loss of information brought on by the global aggregation increases the instability of
explanations. Therefore, we look to local explanations as a better solution.</p>
        <p>
          AGREE appears more promising for local explanations (Table 3), beating or matching the
performance of the k-NN using average weighting in all cases bar one dataset (although this
is the Glass dataset which seems too simple for evaluation). Case alignment aggregations
appear to perform on par with feature overlap metrics proposed by [
          <xref ref-type="bibr" rid="ref13">13</xref>
          ], in terms of explanation
ifdelity. These results are promising as they suggest that overall, the intuition provided by our
aggregation strategy is more intuitive than taking a simple arithmetic mean.
        </p>
      </sec>
      <sec id="sec-8-2">
        <title>7.2. Robustness of Disagreement Measures</title>
        <p>
          Figure 6 shows an example of agreement matrices for a local explanation in the IMDB dataset
( = 500 features) using feature agreement to represent the overlap metrics defined in [
          <xref ref-type="bibr" rid="ref13">13</xref>
          ]
against our case align approach. We observe that as the number of features rises, alignment
measured via feature agreement tends to drop significantly, to almost zero in many cases.
This is not the case for case alignment, which stays relatively stable as  increases. This
behavior is intuitive, owing to the fundamental nature of both metrics. Feature agreement is
sensitive to  features selected for comparison —  increases, the likelihood that these features
do not agree increases. Whereas case align takes into consideration all features in a query to
compare explanations and therefore remains relatively unafected by the number of features in
an instance. In general, across all the datasets, case alignment appears to be more robust against
a rise in dimensionality. This indicates to us that our method may be favourable in realistic
domains where the number of features is often high.
        </p>
      </sec>
    </sec>
    <sec id="sec-9">
      <title>8. Conclusion &amp; Future Work</title>
      <p>Two key contributions were presented in this work: a novel method for evaluating disagreement
between multiple explainers based on local neighbourhood alignment; and AGREE — a novel
explanation aggregation method to formulate robust explanations from the knowledge of various
explainer methods. We evaluate Case Alignment as a measure of disagreement, and the AGREE
method by weighting a k-NN by explanations and observing the degradation or enhancement
of performance. Our approach to measuring disagreement was found to be more robust than
previous feature overlap methods and when settling local disagreements the measure is able to
capture local information to better inform the aggregate explanation using AGREE. For global
disagreements, our experiments found that AGREE does not significantly improve upon simply
taking the average of feature rankings to establish an aggregate importance vector. AGREE
was found to outperform (or match) simply taking the mean feature ranking across all local
explanations in 87.5% of datasets. Another advantage of AGREE is that it is agnostic to both the
explanation methods and disagreement measures used.</p>
      <p>We plan to continue this study by further evaluating AGREE in additional domains and
modalities (such as time-series and image data). In future work, we also propose to extend
AGREE to solve disputes between counterfactuals, as they have been neglected in this paper
but are a popular method for explanation. These studies will be supplemented by working
with our partners in the oil and gas industry to explain anomalies in early warning
timeseries systems on ofshore platforms. In doing so, we will conduct a more complete evaluation
through further quantitative and qualitative studies while evaluating AGREE explanations on
the human-interpretability level.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          [1]
          <string-name>
            <given-names>M. K.</given-names>
            <surname>Belaid</surname>
          </string-name>
          , E. Hüllermeier,
          <string-name>
            <given-names>M.</given-names>
            <surname>Rabus</surname>
          </string-name>
          ,
          <string-name>
            <given-names>R.</given-names>
            <surname>Krestel</surname>
          </string-name>
          ,
          <article-title>Do we need another explainable ai method? toward unifying post-hoc XAI evaluation methods into an interactive and multidimensional benchmark</article-title>
          ,
          <year>2022</year>
          . arXiv:
          <volume>2207</volume>
          .
          <fpage>14160</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          [2]
          <string-name>
            <given-names>R.</given-names>
            <surname>Guidotti</surname>
          </string-name>
          ,
          <article-title>Counterfactual explanations and how to find them: literature review and benchmarking, Data Mining and Knowledge Discovery (</article-title>
          <year>2022</year>
          )
          <fpage>1</fpage>
          -
          <lpage>55</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          [3]
          <string-name>
            <given-names>A.</given-names>
            <surname>Adadi</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Berrada</surname>
          </string-name>
          ,
          <article-title>Peeking inside the black-box: a survey on explainable artificial intelligence (XAI)</article-title>
          ,
          <source>IEEE access 6</source>
          (
          <year>2018</year>
          )
          <fpage>52138</fpage>
          -
          <lpage>52160</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          [4]
          <string-name>
            <given-names>E.</given-names>
            <surname>Cambria</surname>
          </string-name>
          ,
          <string-name>
            <given-names>L.</given-names>
            <surname>Malandri</surname>
          </string-name>
          ,
          <string-name>
            <given-names>F.</given-names>
            <surname>Mercorio</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Mezzanzanica</surname>
          </string-name>
          ,
          <string-name>
            <given-names>N.</given-names>
            <surname>Nobani</surname>
          </string-name>
          ,
          <article-title>A survey on XAI and natural language explanations</article-title>
          ,
          <source>Information Processing &amp; Management</source>
          <volume>60</volume>
          (
          <year>2023</year>
          )
          <fpage>103111</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          [5]
          <string-name>
            <given-names>S. R.</given-names>
            <surname>Islam</surname>
          </string-name>
          ,
          <string-name>
            <given-names>W.</given-names>
            <surname>Eberle</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S. K.</given-names>
            <surname>Ghafoor</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Ahmed</surname>
          </string-name>
          ,
          <article-title>Explainable artificial intelligence approaches: A survey</article-title>
          ,
          <source>arXiv preprint arXiv:2101.09429</source>
          (
          <year>2021</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          [6]
          <string-name>
            <given-names>S.</given-names>
            <surname>Jesus</surname>
          </string-name>
          ,
          <string-name>
            <given-names>C.</given-names>
            <surname>Belém</surname>
          </string-name>
          ,
          <string-name>
            <given-names>V.</given-names>
            <surname>Balayan</surname>
          </string-name>
          , J. a. Bento,
          <string-name>
            <given-names>P.</given-names>
            <surname>Saleiro</surname>
          </string-name>
          ,
          <string-name>
            <given-names>P.</given-names>
            <surname>Bizarro</surname>
          </string-name>
          ,
          <string-name>
            <surname>J.</surname>
          </string-name>
          <article-title>a. Gama, How can i choose an explainer? an application-grounded evaluation of post-hoc explanations</article-title>
          ,
          <source>in: Proceedings of the 2021 ACM Conference on Fairness, Accountability, and Transparency</source>
          , FAccT '21,
          <string-name>
            <surname>Association</surname>
          </string-name>
          for Computing Machinery, New York, NY, USA,
          <year>2021</year>
          , p.
          <fpage>805</fpage>
          -
          <lpage>815</lpage>
          . URL: https://doi.org/10.1145/3442188.3445941. doi:
          <volume>10</volume>
          .1145/3442188.3445941.
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          [7]
          <string-name>
            <given-names>S.</given-names>
            <surname>Upadhyay</surname>
          </string-name>
          ,
          <string-name>
            <given-names>V.</given-names>
            <surname>Isahagian</surname>
          </string-name>
          ,
          <string-name>
            <given-names>V.</given-names>
            <surname>Muthusamy</surname>
          </string-name>
          ,
          <string-name>
            <given-names>Y.</given-names>
            <surname>Rizk</surname>
          </string-name>
          ,
          <article-title>Extending lime for business process automation</article-title>
          ,
          <source>arXiv preprint arXiv:2108.04371</source>
          (
          <year>2021</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation>
          [8]
          <string-name>
            <given-names>K.</given-names>
            <surname>Simonyan</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Vedaldi</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Zisserman</surname>
          </string-name>
          ,
          <article-title>Deep inside convolutional networks: Visualising image classification models and saliency maps</article-title>
          ,
          <source>arXiv preprint arXiv:1312.6034</source>
          (
          <year>2013</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref9">
        <mixed-citation>
          [9]
          <string-name>
            <surname>A. Das</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          <string-name>
            <surname>Rad</surname>
          </string-name>
          ,
          <article-title>Opportunities and challenges in explainable artificial intelligence (XAI): A survey</article-title>
          , arXiv preprint arXiv:
          <year>2006</year>
          .
          <volume>11371</volume>
          (
          <year>2020</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref10">
        <mixed-citation>
          [10]
          <string-name>
            <given-names>E. M.</given-names>
            <surname>Kenny</surname>
          </string-name>
          ,
          <string-name>
            <given-names>E. D.</given-names>
            <surname>Delaney</surname>
          </string-name>
          ,
          <string-name>
            <given-names>D.</given-names>
            <surname>Greene</surname>
          </string-name>
          , M. T. Keane,
          <article-title>Post-hoc explanation options for XAI in deep learning: The insight centre for data analytics perspective, in: Pattern Recognition</article-title>
          .
          <source>ICPR International Workshops and Challenges: Virtual Event, January 10-15</source>
          ,
          <year>2021</year>
          , Proceedings,
          <string-name>
            <surname>Part</surname>
            <given-names>III</given-names>
          </string-name>
          , Springer,
          <year>2021</year>
          , pp.
          <fpage>20</fpage>
          -
          <lpage>34</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref11">
        <mixed-citation>
          [11]
          <string-name>
            <given-names>E.</given-names>
            <surname>Tjoa</surname>
          </string-name>
          ,
          <string-name>
            <given-names>C.</given-names>
            <surname>Guan</surname>
          </string-name>
          ,
          <article-title>A survey on explainable artificial intelligence (XAI): Toward medical XAI, IEEE transactions on neural networks and learning systems 32 (</article-title>
          <year>2020</year>
          )
          <fpage>4793</fpage>
          -
          <lpage>4813</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref12">
        <mixed-citation>
          [12]
          <string-name>
            <given-names>M.</given-names>
            <surname>Ivanovs</surname>
          </string-name>
          ,
          <string-name>
            <given-names>R.</given-names>
            <surname>Kadikis</surname>
          </string-name>
          ,
          <string-name>
            <given-names>K.</given-names>
            <surname>Ozols</surname>
          </string-name>
          ,
          <article-title>Perturbation-based methods for explaining deep neural networks: A survey</article-title>
          ,
          <source>Pattern Recognition Letters</source>
          <volume>150</volume>
          (
          <year>2021</year>
          )
          <fpage>228</fpage>
          -
          <lpage>234</lpage>
          . URL: https://www.sciencedirect.com/science/article/pii/S0167865521002440. doi:https://doi. org/10.1016/j.patrec.
          <year>2021</year>
          .
          <volume>06</volume>
          .030.
        </mixed-citation>
      </ref>
      <ref id="ref13">
        <mixed-citation>
          [13]
          <string-name>
            <given-names>S.</given-names>
            <surname>Krishna</surname>
          </string-name>
          , T. Han,
          <string-name>
            <surname>A</surname>
          </string-name>
          . Gu,
          <string-name>
            <given-names>J.</given-names>
            <surname>Pombra</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Jabbari</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Wu</surname>
          </string-name>
          ,
          <string-name>
            <given-names>H.</given-names>
            <surname>Lakkaraju</surname>
          </string-name>
          ,
          <article-title>The disagreement problem in explainable machine learning: A practitioner's perspective</article-title>
          ,
          <source>arXiv preprint arXiv:2202.01602</source>
          (
          <year>2022</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref14">
        <mixed-citation>
          [14]
          <string-name>
            <given-names>M. T.</given-names>
            <surname>Ribeiro</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Singh</surname>
          </string-name>
          ,
          <string-name>
            <given-names>C.</given-names>
            <surname>Guestrin</surname>
          </string-name>
          ,
          <article-title>"why should I trust you?": Explaining the predictions of any classifier</article-title>
          ,
          <source>CoRR abs/1602</source>
          .04938 (
          <year>2016</year>
          ). URL: http://arxiv.org/abs/1602.04938. arXiv:
          <volume>1602</volume>
          .
          <fpage>04938</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref15">
        <mixed-citation>
          [15]
          <string-name>
            <given-names>S.</given-names>
            <surname>Lundberg</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.-I.</given-names>
            <surname>Lee</surname>
          </string-name>
          ,
          <article-title>A unified approach to interpreting model predictions</article-title>
          ,
          <year>2017</year>
          . URL: https://arxiv.org/abs/1705.07874. doi:
          <volume>10</volume>
          .48550/ARXIV.1705.07874.
        </mixed-citation>
      </ref>
      <ref id="ref16">
        <mixed-citation>
          [16]
          <string-name>
            <given-names>M.</given-names>
            <surname>Sundararajan</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Taly</surname>
          </string-name>
          ,
          <string-name>
            <given-names>Q.</given-names>
            <surname>Yan</surname>
          </string-name>
          ,
          <article-title>Axiomatic attribution for deep networks</article-title>
          ,
          <source>CoRR abs/1703</source>
          .01365 (
          <year>2017</year>
          ). URL: http://arxiv.org/abs/1703.01365. arXiv:
          <volume>1703</volume>
          .
          <fpage>01365</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref17">
        <mixed-citation>
          [17]
          <string-name>
            <surname>Liver</surname>
            <given-names>Disorders</given-names>
          </string-name>
          ,
          <source>UCI Machine Learning Repository</source>
          ,
          <year>1990</year>
          . DOI: https://doi.org/10.24432/C54G67.
        </mixed-citation>
      </ref>
      <ref id="ref18">
        <mixed-citation>
          [18]
          <string-name>
            <given-names>S. R.</given-names>
            <surname>Safavian</surname>
          </string-name>
          ,
          <string-name>
            <given-names>D.</given-names>
            <surname>Landgrebe</surname>
          </string-name>
          ,
          <article-title>A survey of decision tree classifier methodology</article-title>
          ,
          <source>IEEE transactions on systems, man, and cybernetics 21</source>
          (
          <year>1991</year>
          )
          <fpage>660</fpage>
          -
          <lpage>674</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref19">
        <mixed-citation>
          [19]
          <string-name>
            <given-names>R.</given-names>
            <surname>Tibshirani</surname>
          </string-name>
          ,
          <article-title>Regression shrinkage and selection via the lasso</article-title>
          ,
          <source>Journal of the Royal Statistical Society: Series B (Methodological) 58</source>
          (
          <year>1996</year>
          )
          <fpage>267</fpage>
          -
          <lpage>288</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref20">
        <mixed-citation>
          [20]
          <string-name>
            <given-names>P.</given-names>
            <surname>McCullagh</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J. A.</given-names>
            <surname>Nelder</surname>
          </string-name>
          ,
          <article-title>Generalized linear models</article-title>
          , volume
          <volume>37</volume>
          of, Monographs on statistics and applied probability (
          <year>1989</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref21">
        <mixed-citation>
          [21]
          <string-name>
            <given-names>J. van der</given-names>
            <surname>Waa</surname>
          </string-name>
          , E. Nieuwburg,
          <string-name>
            <given-names>A.</given-names>
            <surname>Cremers</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Neerincx</surname>
          </string-name>
          ,
          <string-name>
            <surname>Evaluating</surname>
            <given-names>XAI</given-names>
          </string-name>
          :
          <article-title>A comparison of rule-based and example-based explanations</article-title>
          ,
          <source>Artificial Intelligence</source>
          <volume>291</volume>
          (
          <year>2021</year>
          )
          <fpage>103404</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref22">
        <mixed-citation>
          [22]
          <string-name>
            <given-names>M. T.</given-names>
            <surname>Ribeiro</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Singh</surname>
          </string-name>
          ,
          <string-name>
            <given-names>C.</given-names>
            <surname>Guestrin</surname>
          </string-name>
          ,
          <article-title>Anchors: High-precision model-agnostic explanations</article-title>
          ,
          <source>in: Proceedings of the AAAI conference on artificial intelligence</source>
          , volume
          <volume>32</volume>
          ,
          <year>2018</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref23">
        <mixed-citation>
          [23]
          <string-name>
            <given-names>V.</given-names>
            <surname>Petsiuk</surname>
          </string-name>
          ,
          <string-name>
            <surname>A. Das</surname>
            ,
            <given-names>K.</given-names>
          </string-name>
          <string-name>
            <surname>Saenko</surname>
          </string-name>
          ,
          <article-title>Rise: Randomized input sampling for explanation of blackbox models</article-title>
          , arXiv preprint arXiv:
          <year>1806</year>
          .
          <volume>07421</volume>
          (
          <year>2018</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref24">
        <mixed-citation>
          [24]
          <string-name>
            <given-names>R. R.</given-names>
            <surname>Selvaraju</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Cogswell</surname>
          </string-name>
          ,
          <string-name>
            <surname>A. Das</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          <string-name>
            <surname>Vedantam</surname>
            ,
            <given-names>D.</given-names>
          </string-name>
          <string-name>
            <surname>Parikh</surname>
            ,
            <given-names>D.</given-names>
          </string-name>
          <string-name>
            <surname>Batra</surname>
          </string-name>
          , Grad-cam:
          <article-title>Visual explanations from deep networks via gradient-based localization</article-title>
          ,
          <source>in: Proceedings of the IEEE international conference on computer vision</source>
          ,
          <year>2017</year>
          , pp.
          <fpage>618</fpage>
          -
          <lpage>626</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref25">
        <mixed-citation>
          [25]
          <string-name>
            <given-names>D.</given-names>
            <surname>Smilkov</surname>
          </string-name>
          ,
          <string-name>
            <given-names>N.</given-names>
            <surname>Thorat</surname>
          </string-name>
          ,
          <string-name>
            <given-names>B.</given-names>
            <surname>Kim</surname>
          </string-name>
          ,
          <string-name>
            <given-names>F.</given-names>
            <surname>Viégas</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Wattenberg</surname>
          </string-name>
          ,
          <article-title>Smoothgrad: removing noise by adding noise</article-title>
          ,
          <source>arXiv preprint arXiv:1706.03825</source>
          (
          <year>2017</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref26">
        <mixed-citation>
          [26]
          <string-name>
            <given-names>S.</given-names>
            <surname>Bach</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Binder</surname>
          </string-name>
          ,
          <string-name>
            <given-names>G.</given-names>
            <surname>Montavon</surname>
          </string-name>
          ,
          <string-name>
            <given-names>F.</given-names>
            <surname>Klauschen</surname>
          </string-name>
          ,
          <string-name>
            <surname>K.-R. Müller</surname>
          </string-name>
          , W. Samek,
          <article-title>On pixel-wise explanations for non-linear classifier decisions by layer-wise relevance propagation</article-title>
          ,
          <source>PloS one 10</source>
          (
          <year>2015</year>
          )
          <article-title>e0130140</article-title>
          .
        </mixed-citation>
      </ref>
      <ref id="ref27">
        <mixed-citation>
          [27]
          <string-name>
            <given-names>I. E.</given-names>
            <surname>Nielsen</surname>
          </string-name>
          ,
          <string-name>
            <given-names>D.</given-names>
            <surname>Dera</surname>
          </string-name>
          , G. Rasool,
          <string-name>
            <given-names>R. P.</given-names>
            <surname>Ramachandran</surname>
          </string-name>
          ,
          <string-name>
            <given-names>N. C.</given-names>
            <surname>Bouaynaya</surname>
          </string-name>
          ,
          <article-title>Robust explainability: A tutorial on gradient-based attribution methods for deep neural networks</article-title>
          ,
          <source>IEEE Signal Processing Magazine</source>
          <volume>39</volume>
          (
          <year>2022</year>
          )
          <fpage>73</fpage>
          -
          <lpage>84</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref28">
        <mixed-citation>
          [28]
          <string-name>
            <given-names>K.</given-names>
            <surname>Abhishek</surname>
          </string-name>
          ,
          <string-name>
            <given-names>D.</given-names>
            <surname>Kamath</surname>
          </string-name>
          ,
          <article-title>Attribution-based XAI methods in computer vision: A review</article-title>
          ,
          <source>arXiv preprint arXiv:2211.14736</source>
          (
          <year>2022</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref29">
        <mixed-citation>
          [29]
          <string-name>
            <given-names>M. T.</given-names>
            <surname>Keane</surname>
          </string-name>
          ,
          <string-name>
            <given-names>B.</given-names>
            <surname>Smyth</surname>
          </string-name>
          ,
          <article-title>Good counterfactuals and where to find them: A case-based technique for generating counterfactuals for explainable ai (XAI)</article-title>
          ,
          <source>in: Case-Based Reasoning Research and Development: 28th International Conference, ICCBR</source>
          <year>2020</year>
          , Salamanca, Spain, June 8-12,
          <year>2020</year>
          , Proceedings 28, Springer,
          <year>2020</year>
          , pp.
          <fpage>163</fpage>
          -
          <lpage>178</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref30">
        <mixed-citation>
          [30]
          <string-name>
            <given-names>E.</given-names>
            <surname>Amparore</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Perotti</surname>
          </string-name>
          ,
          <string-name>
            <given-names>P.</given-names>
            <surname>Bajardi</surname>
          </string-name>
          ,
          <article-title>To trust or not to trust an explanation: using leaf to evaluate local linear XAI methods</article-title>
          ,
          <source>PeerJ Computer Science</source>
          <volume>7</volume>
          (
          <year>2021</year>
          )
          <article-title>e479</article-title>
          .
        </mixed-citation>
      </ref>
      <ref id="ref31">
        <mixed-citation>
          [31]
          <string-name>
            <given-names>P.</given-names>
            <surname>Lopes</surname>
          </string-name>
          ,
          <string-name>
            <given-names>E.</given-names>
            <surname>Silva</surname>
          </string-name>
          ,
          <string-name>
            <given-names>C.</given-names>
            <surname>Braga</surname>
          </string-name>
          ,
          <string-name>
            <given-names>T.</given-names>
            <surname>Oliveira</surname>
          </string-name>
          , L. Rosado,
          <article-title>XAI systems evaluation: A review of human and computer-centred methods</article-title>
          ,
          <source>Applied Sciences</source>
          <volume>12</volume>
          (
          <year>2022</year>
          )
          <fpage>9423</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref32">
        <mixed-citation>
          [32]
          <string-name>
            <given-names>S.</given-names>
            <surname>Roy</surname>
          </string-name>
          ,
          <string-name>
            <given-names>G.</given-names>
            <surname>Laberge</surname>
          </string-name>
          ,
          <string-name>
            <given-names>B.</given-names>
            <surname>Roy</surname>
          </string-name>
          ,
          <string-name>
            <given-names>F.</given-names>
            <surname>Khomh</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Nikanjam</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Mondal</surname>
          </string-name>
          ,
          <article-title>Why don't XAI techniques agree? characterizing the disagreements between post-hoc explanations of defect predictions</article-title>
          ,
          <source>in: 2022 IEEE International Conference on Software Maintenance and Evolution (ICSME)</source>
          ,
          <year>2022</year>
          , pp.
          <fpage>444</fpage>
          -
          <lpage>448</lpage>
          . doi:
          <volume>10</volume>
          .1109/ICSME55016.
          <year>2022</year>
          .
          <volume>00056</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref33">
        <mixed-citation>
          [33]
          <string-name>
            <given-names>D.</given-names>
            <surname>Brughmans</surname>
          </string-name>
          ,
          <string-name>
            <given-names>L.</given-names>
            <surname>Melis</surname>
          </string-name>
          ,
          <string-name>
            <given-names>D.</given-names>
            <surname>Martens</surname>
          </string-name>
          ,
          <article-title>Disagreement amongst counterfactual explanations: How transparency can be deceptive</article-title>
          ,
          <source>arXiv preprint arXiv:2304.12667</source>
          (
          <year>2023</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref34">
        <mixed-citation>
          [34]
          <string-name>
            <given-names>M.</given-names>
            <surname>Raghunandan</surname>
          </string-name>
          ,
          <string-name>
            <given-names>N.</given-names>
            <surname>Wiratunga</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Chakraborti</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Massie</surname>
          </string-name>
          ,
          <string-name>
            <given-names>D.</given-names>
            <surname>Khemani</surname>
          </string-name>
          ,
          <article-title>Evaluation measures for TCBR systems</article-title>
          ,
          <source>in: Advances in Case-Based Reasoning: 9th European Conference, ECCBR</source>
          <year>2008</year>
          , Trier, Germany, September 1-
          <issue>4</issue>
          ,
          <year>2008</year>
          . Proceedings 9, Springer,
          <year>2008</year>
          , pp.
          <fpage>444</fpage>
          -
          <lpage>458</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref35">
        <mixed-citation>
          [35]
          <string-name>
            <given-names>D.</given-names>
            <surname>Dua</surname>
          </string-name>
          ,
          <string-name>
            <surname>C. Graf,</surname>
          </string-name>
          <article-title>UCI machine learning repository</article-title>
          ,
          <year>2017</year>
          . URL: http://archive.ics.uci.edu/ml.
        </mixed-citation>
      </ref>
      <ref id="ref36">
        <mixed-citation>
          [36]
          <string-name>
            <given-names>L. S.</given-names>
            <surname>Shapley</surname>
          </string-name>
          ,
          <article-title>A value for n-person games</article-title>
          , in: Contributions to the
          <source>Theory of Games</source>
          ,
          <year>1953</year>
          , pp.
          <fpage>307</fpage>
          -
          <lpage>317</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref37">
        <mixed-citation>
          [37]
          <string-name>
            <given-names>D.</given-names>
            <surname>Slack</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Hilgard</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Singh</surname>
          </string-name>
          ,
          <string-name>
            <given-names>H.</given-names>
            <surname>Lakkaraju</surname>
          </string-name>
          ,
          <article-title>Reliable post hoc explanations: Modeling uncertainty in explainability</article-title>
          ,
          <source>Advances in neural information processing systems</source>
          <volume>34</volume>
          (
          <year>2021</year>
          )
          <fpage>9391</fpage>
          -
          <lpage>9404</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref38">
        <mixed-citation>
          [38]
          <string-name>
            <given-names>S. M.</given-names>
            <surname>Lundberg</surname>
          </string-name>
          ,
          <string-name>
            <given-names>G. G.</given-names>
            <surname>Erion</surname>
          </string-name>
          ,
          <string-name>
            <surname>S.-I. Lee</surname>
          </string-name>
          ,
          <article-title>Consistent individualized feature attribution for tree ensembles</article-title>
          , arXiv preprint arXiv:
          <year>1802</year>
          .
          <volume>03888</volume>
          (
          <year>2018</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref39">
        <mixed-citation>
          [39]
          <string-name>
            <given-names>A.</given-names>
            <surname>Shrikumar</surname>
          </string-name>
          ,
          <string-name>
            <given-names>P.</given-names>
            <surname>Greenside</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Kundaje</surname>
          </string-name>
          ,
          <article-title>Learning important features through propagating activation diferences</article-title>
          , in: D.
          <string-name>
            <surname>Precup</surname>
            ,
            <given-names>Y. W.</given-names>
          </string-name>
          <string-name>
            <surname>Teh</surname>
          </string-name>
          (Eds.),
          <source>Proceedings of the 34th International Conference on Machine Learning</source>
          , volume
          <volume>70</volume>
          <source>of Proceedings of Machine Learning Research, PMLR</source>
          ,
          <year>2017</year>
          , pp.
          <fpage>3145</fpage>
          -
          <lpage>3153</lpage>
          . URL: https://proceedings.mlr.press/v70/shrikumar17a.html.
        </mixed-citation>
      </ref>
      <ref id="ref40">
        <mixed-citation>
          [40]
          <string-name>
            <given-names>M.</given-names>
            <surname>Sundararajan</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Taly</surname>
          </string-name>
          ,
          <string-name>
            <given-names>Q.</given-names>
            <surname>Yan</surname>
          </string-name>
          ,
          <article-title>Axiomatic attribution for deep networks</article-title>
          ,
          <source>in: International conference on machine learning, PMLR</source>
          ,
          <year>2017</year>
          , pp.
          <fpage>3319</fpage>
          -
          <lpage>3328</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref41">
        <mixed-citation>
          [41]
          <string-name>
            <given-names>P.</given-names>
            <surname>Sturmfels</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Lundberg</surname>
          </string-name>
          ,
          <string-name>
            <surname>S.-I. Lee</surname>
          </string-name>
          ,
          <article-title>Visualizing the impact of feature attribution baselines</article-title>
          ,
          <source>Distill</source>
          <volume>5</volume>
          (
          <year>2020</year>
          )
          <article-title>e22</article-title>
          .
        </mixed-citation>
      </ref>
      <ref id="ref42">
        <mixed-citation>
          [42]
          <string-name>
            <given-names>G.</given-names>
            <surname>Plumb</surname>
          </string-name>
          ,
          <string-name>
            <given-names>D.</given-names>
            <surname>Molitor</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A. S.</given-names>
            <surname>Talwalkar</surname>
          </string-name>
          ,
          <article-title>Model agnostic supervised local explanations</article-title>
          ,
          <source>Advances in neural information processing systems</source>
          <volume>31</volume>
          (
          <year>2018</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref43">
        <mixed-citation>
          [43]
          <string-name>
            <given-names>A.</given-names>
            <surname>Bloniarz</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Talwalkar</surname>
          </string-name>
          ,
          <string-name>
            <given-names>B.</given-names>
            <surname>Yu</surname>
          </string-name>
          ,
          <string-name>
            <given-names>C.</given-names>
            <surname>Wu</surname>
          </string-name>
          ,
          <article-title>Supervised neighborhoods for distributed nonparametric regression</article-title>
          ,
          <source>in: Artificial Intelligence and Statistics</source>
          , PMLR,
          <year>2016</year>
          , pp.
          <fpage>1450</fpage>
          -
          <lpage>1459</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref44">
        <mixed-citation>
          [44]
          <string-name>
            <given-names>J.</given-names>
            <surname>Kazemitabar</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Amini</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Bloniarz</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A. S.</given-names>
            <surname>Talwalkar</surname>
          </string-name>
          ,
          <article-title>Variable importance using decision trees</article-title>
          ,
          <source>Advances in neural information processing systems</source>
          <volume>30</volume>
          (
          <year>2017</year>
          ).
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>