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  <front>
    <journal-meta />
    <article-meta>
      <article-id pub-id-type="doi">10.1038/s42256-023-00626-4</article-id>
      <title-group>
        <article-title>CornellNLP at CheckThat! 2025: Hybrid Llama-GPT-4 Ensembles with Confidence Filtering for Numerical Claim Verification⋆</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Lea Duesterwald</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Adi Arora</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Claire Cardie</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Cornell University Ann S. Bowers College of Computing and Information Science</institution>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2025</year>
      </pub-date>
      <volume>37</volume>
      <fpage>0000</fpage>
      <lpage>0002</lpage>
      <abstract>
        <p>Claim verification is an important challenge and remains dificult, particularly in the space of numerical claims, both for large language models (LLMs) and human annotators. This paper presents our participation in the CheckThat! Lab Task 3: Fact-Checking Numerical Claims shared task which aims to advance fact checking systems on claims that contain numerical and temporal details. We show that large LLMs like GPT-4 are able to rate their confidence in their predictions such that confidence ratings are indicative of model performance. We use this finding to develop an ensembling method, combining the predictions of GPT-4 with few-shot prompting and a fine-tuned Llama 2 7B model via a voting mechanism based on model self-confidence ratings. While our ifnal ensemble achieved moderate performance overall, our results demonstrate a novel and efective use of LLM self-confidence as a lightweight way to integrate large LLMs with other models to improve claim verification.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;Numerical Claim Verification</kwd>
        <kwd>Large Language Model</kwd>
        <kwd>GPT-4</kwd>
        <kwd>Llama 2</kwd>
        <kwd>Self-Confidence Estimation</kwd>
        <kwd>Ensemble Methods</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        Fact checking systems are critical for stopping the spread of misinformation and automating fact
checking has been an important area of research, especially recently [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. Evaluating numerical claims
is of particular importance [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]. However, numerical claims have been shown to be particularly dificult
to verify, both for annotators [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ] and for large language models (LLMs) [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ].
      </p>
      <p>
        The CheckThat! Task 3 Challenge [5, 6, 7], Fact-Checking Numerical Claims, focuses on evaluating
claims that contain numerical and temporal details. The task provides training, development, and
test sets developed from the QuanTemp dataset, a diverse, multi-domain dataset of numerical claims
with detailed metadata and evidence collections [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. The aim of the task is to improve the ability of
NLP systems to process and understand numerical claims and to verify these claims. In this paper we
describe our participation in Task 3 of the CheckThat! Lab.
      </p>
      <p>With LLMs becoming more powerful, they now show promise to read and understand numerical
claims, reason about the claim, and verify the correctness of the claim. However, these LLMs are not
perfect as they can often make mistakes or hallucinate [8]. To further complicate their application
to claim verification, LLMs can also hallucinate confidently, producing incorrect responses with full
confidence and without the ability to determine their own lack of knowledge [9].</p>
      <p>We sought to take a closer look at an LLM’s ability to determine its level of confidence in the specific
context of numerical claim verification. More specifically, we sought to prompt GPT-4 to not only
predict a label for each claim, but also produce a self-confidence rating that should be indicative of
correctness. If LLMs do possess this ability, we can leverage this to improve claim verification, ultimately
combining a large LLM like GPT-4 with other models to selectively replace low-confidence predictions
from GPT, providing an eficient way to increase performance without adding significant complexity.</p>
      <p>In our work, we developed an ensemble of GPT-4 and a fine-tuned Llama 2 7B model, employing
a voting mechanism based on self-confidence ratings, with the goal of improving performance on
numerical claim verification.</p>
      <p>The remainder of the paper is organized as follows: Section 2 reviews related work. Section 3 discusses
our methodology, detailing the ensemble method and each individual component. Section 4 contains
our results. Discussion and conclusions are presented in Section 5.</p>
    </sec>
    <sec id="sec-2">
      <title>2. Related Work</title>
      <p>
        Automated fact checking typically includes a pipeline consisting of claim detection, evidence retrieval,
and finally verdict prediction. This verdict prediction often involves natural language inference (NLI)
[10, 11, 12] making automation of fact checking an important application of LLMS. Verifying numerical
remains a continuing challenge, both for human annotators and models [
        <xref ref-type="bibr" rid="ref3 ref4">3, 4</xref>
        ]. Claims that contain
numerical expressions or temporal aspects also present a unique challenge and traditional fact-checking
datasets often do not cover numerical expressions and are thus not representative of numerical claim
verification. As a dataset focused exclusively on numerical claims QuanTemp addresses this gap,
providing multi-domain data containing various types of numerical claims [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ].
      </p>
      <p>Powerful LLMs with huge knowledge bases provide the capability for fact verification [ 13]. However,
LLMs still struggle with hallucinations [8] that hinder their ability to be applied to this task of numerical
claim verification. Further, LLMs also often exhibit overconfidence in their outputs, even in incorrect
outputs and achieving accurate calibration remains a challenge in many areas [14].</p>
      <p>Prompt engineering and designing the optimal prompt for a task has been shown to significantly
improve LLM performance, especially for tasks that require factual accuracy [15]. In particular, few-shot
prompting has been shown to significantly enhance model performance on classification tasks without
task-specific fine-tuning [ 16]. Beyond general-purpose LLMs, adapting large models to specific tasks
such as fact-checking can improve model performance [17]. Specifically, parameter-eficient fine tuning
(PEFT) methods such as LoRA can reduce computation costs while still retaining strong performance
on specific tasks [ 18, 19, 20]. Ensemble methods provide the opportunity to improve performance and
robustness by combining multiple models. Combining diferent LLMs such as GPT-4 and Llama can
lead to improved accuracy across diferent NLP tasks [21, 22].</p>
      <p>Our work leverages few-shot prompting with GPT-4 and LoRA for eficient fine-tuning of Llama 2
7B to independently optimize each model individually. We then combine these models in an ensemble
system. This approach allows us to capture the strengths of both models to improve overall performance
through the ensemble.</p>
    </sec>
    <sec id="sec-3">
      <title>3. Methodology</title>
      <sec id="sec-3-1">
        <title>3.1. Ensemble Overview</title>
        <p>To classify numerical claims, we used an ensemble method which employed a voting mechanism
between two models: a fine-tuned Llama 2 7B model and a GPT-4 model with few-shot prompting. The
voting mechanism employs self-confidence ratings from GPT-4 in its predictions to settle disagreements,
selecting GPT’s predicted label when it indicated a high confidence in its answer and Llama’s predicted
label otherwise. Both Llama 2 7B and GPT-4 were separately optimized to achieve the best performance
on a development test set and then combined via the voting mechanism on the final test set. The datasets
used for both fine-tuning Llama and developing the few shot prompts for GPT-4 were the provided
training and validation datasets with the included top-k BM25 evidences. Both methods made initial
predictions individually on the provided test set which included the claims, decomposed sub-questions,
and top-k BM25 evidences.</p>
      </sec>
      <sec id="sec-3-2">
        <title>3.2. Fine-Tuning Llama</title>
        <p>We fine-tuned a 7B-parameter Llama 2 model (huggyLlama/llama-7b) using LoRA adapters and a
4-bit quantization (to increase the eficiency of training by reducing memory usage). The model was
ifne-tuned on the provided training set. The input was structured as a prompt with the form [Claim]:
.... [Evidences]: ... [Label]: ... and the model was trained for a causal language modeling task. The
ifne-tuning was performed over 3 epochs with a batch size of 1, learning rate of 2e-4 and using the
paged_adamw_32bit optimizer.</p>
        <p>To evaluate the model during development, we extracted a hold-out test set, taking 10% of data from
both the provided train and validation sets for new data sizes of 8,942 for the train set, 2,776 for the
validation set, and 1301 for the test set. The model was fine-tuned on this new train and validation set
and evaluated on the hold-out test set. However, as part of the final ensemble when making predictions
on the actual test set, we used the model fine-tuned on all of the available train and validation data.</p>
      </sec>
      <sec id="sec-3-3">
        <title>3.3. Few-shot prompting with GPT-4</title>
        <p>We employed few-shot prompting, providing a few examples from each label class from the development
set, to improve the predictions made by GPT-4. The baseline model we used was GPT-4 Turbo with
default parameter values due to its reasoning abilities and efectiveness in few-shot settings. The
baseline prompt was:
You are a numerical fact-checking assistant. For the given numerical claim and evidence, please decide if
the claim is True (2), False (0), or Half True/False (conflicting) (1)
For help analyzing the claim, please reference the following examples, separated by ∼ s
Note: The above part of the prompt does not include the sections of the prompt which provide the claim
and evidences on which to predict or the instructions for formatting the response. These were omitted
above for brevity as they are the same across all prompt variations used during prompt development.</p>
        <p>In order to maximize the predictions of GPT-4 on the test set, we investigated augmenting the baseline
prompts in several ways. The diferent prompt variations we evaluated were:
1. 10 Examples: Including more examples (10 instead of 2 per class) in the few-shot examples.
2. Focus Numerical: Directing the model to focus on the numerical aspects (to determine whether
the model was getting distracted by wording or unimportant details rather than focusing on the
numerical aspects of the claim).
3. Focus Claim Decomp: Directing the model to decompose the claim into sub-claims on its own (to
encourage claim-decomposition reasoning in the model).
4. Annotated Examples: Providing human-produced annotations for each of the few-shot examples
explaining why it received the label it did.
5. Baseline + Reasoning: Baseline prompt with 2 examples per class using GPT-4o-mini instead of</p>
        <p>GPT-4 Turbo, reasoning_efort = medium (to leverage reasoning capabilities).</p>
        <p>6. 10 Examples + Reasoning: 10 examples per class, using GPT-4o-mini.</p>
        <p>To test these prompts, we created a development test set of the first 100 examples from the validation
set and calculated the F1 scores of predictions generated with each prompt variation on this test set.
This smaller test set was created to reduce cost and the number of calls to the OpenAI API.</p>
        <p>To produce the best GPT-4 predictions in the final ensemble, we selected the prompt variation that
had the highest F1 score in this development test set. We found the best performance using GPT-4
Turbo with 10 examples per class in the few-shot examples. While we found in testing that increasing
the number of examples provided improved performance, for the final predictions on the test set we
used 3 examples per class rather than 10 to reduce the token size of the prompt and associated cost
while still including an increased number of examples over our baseline of 2.</p>
        <p>Confidence Self-Rating Prompt : In addition to the optimized few-shot prompt we developed for
the final ensemble (baseline prompt + 3 examples per class), we further prompted the model to rank its
confidence in its prediction on a scale of 1 to 5 where 1 indicated the model was unsure of its predicted
label and 5 meant the model was completely sure its prediction was correct. The complete prompt used
to make predictions on the final test set was thus:
You are a numerical fact-checking assistant. For the given numerical claim and evidence, please decide if
the claim is True (2), False (0), or Half True/False (conflicting) (1). You will be provided with the claim, the
claim broken down into its sub-questions, and the top 5 documents which provide evidence/data. Your task
is to evaluate the claim based on this provided data.</p>
        <p>CLAIM (to be evaluated by you): &lt; &lt; &lt; [claim] &gt; &gt; &gt;
SUB-QUESTIONS (that the claim has been broken down into): &lt; &lt; &lt; [sub-questions] &gt; &gt; &gt;
TOP 5 EVIDENCES (that you will be evaluating the claim on) &lt; &lt; &lt; [first 5 top-k evidences] &gt; &gt; &gt;
When you are answering, please also rank your confidence in your evaluation of the claim on a scale of 1-5
where 1 means there is some unclarity in the claim or evidences and you are not sure of your evaluation
and 5 means you are 100% sure you are correct in your evaluation"
Please respond with either 0, 1, or 2 based on the labels where 0 means you are classifying the claim as false,
1 means you are classifying the claim as half true/false (i.e., conflicting), and 2 means you are classifying
the claim as true
When formatting your answer, please provide your verdict (as a number 0-2 corresponding to false,
conflicting, or true) and your confidence rating (number 1-5). i.e., your final answer should have the format (0, 5)
which would correspond to a verdict of 0 (false) and a confidence rating of 5 (completely sure). Please ONLY
answer with this tuple and do not include anything else beyond this tuple in your response
For help analyzing the claim, please reference the following examples, separated by ∼ s
[few shot examples: 3 examples from every class]</p>
        <p>Thus all predictions made by GPT-4 on the final test set had a self-confidence rating associated with
the predicted label.</p>
      </sec>
      <sec id="sec-3-4">
        <title>3.4. Confidence Self-Rating Analysis</title>
        <p>As part of our model ensemble development, we sought to investigate whether GPT-4 had a sense of
its own correctness, i.e., whether the model can determine when it has clearly understood the claim
and evidences and can make a correct prediction for the verification of this claim and thus return a
high self-confidence rating. Conversely, we also examined whether the model can determine when it is
unsure of the predicted label, perhaps even guessing, meaning it is much more likely to be incorrect
and thus return a lower self-confidence rating.</p>
        <p>To determine whether the self-confidence ratings are indicative of the correctness of the model’s
prediction on that given example, we evaluated how performance changed as the confidence ratings
increased on the predictions made on the development test set by GPT-4o mini using the prompt with
10 examples per class label in the few-shot examples. We compared the performance on subsets of the
test set for which the model indicated a confidence of at least a certain value (i.e., the performance
on only examples for which the self-confidence rating was greater than or equal to 1, 2, 3, 4, and 5,
respectively).</p>
        <p>Additionally, we evaluated whether the confidence ratings could be used as a predictor of accuracy.
Using the same set of predictions, actual values, and confidence self-ratings, we fitted a logistic regression
model to predict correctness (1 or 0 corresponding to whether predicted label == actual label) from the
confidence self-ratings on the development test set. From this model we extracted the coeficient on the
confidence predictor to determine the strength of the relationship between confidence and accuracy
and we calculated the p-value using a permutation test.</p>
      </sec>
      <sec id="sec-3-5">
        <title>3.5. Voting Mechanism for Ensemble</title>
        <p>To determine the final predicted label, we used the predictions from both the fine-tuned Llama model as
well as the GPT-4 model, using a voting mechanism based on GPT self-confidence ratings to determine
the label when the model predictions disagreed. We established a confidence rating threshold, in which
the final predicted label was set to the prediction from GPT-4 when the self-confidence rating was
greater than or equal to the threshold and the prediction from Llama when the confidence rating was
below the threshold. For the final voting mechanism, we set this threshold to 5 to ensure that ties were
only decided in favor of GPT predictions when GPT was highly confident the corresponding prediction
was correct. For improved eficiency, we only computed Llama predictions on examples for which
GPT did not return a self-confidence rating of 5 (as the voting mechanism would always return GPT’s
predicted label for these, whether or not the prediction of Llama agrees).</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>4. Results</title>
      <sec id="sec-4-1">
        <title>4.1. Model Results</title>
        <p>Fine-tuned Llama: The macro average F1 score of only the fine-tuned Llama model (fine-tuned on
data excluding the hold-out set we created) on the hold-out test set of 1301 examples was 0.594 and the
overall accuracy was 0.685 [Table 1]. Class-specific F1 scores and accuracies are shown in Table 1 and
Figure 1. F1 scores and accuracy were the highest in the False class (0.822, and 0.858 respectively) with
performances in the True class (0.590, and 0.6382) and Conflicting class (0.371, and 0.310) being lower.
These results suggest a bias toward negative predictions, likely caused by a class imbalance with False
making up 58% of the dataset. Figure 1 reflects this same bias toward False predictions, showing that
the model frequently misclassified both Half and True claims as False.</p>
        <p>GPT-4 with Few-Shot Prompting: The macro average F1 scores and accuracies of diferent prompt
variations on the development test set we created are shown in Table 2. The best results were achieved
with the 10 examples prompt (F1: 0.550, accuracy: 0.62). For both GPT-4 Turbo and GPT-4o mini,
increasing the number of examples from 2 to 10 per class in the few-shot prompt led to an improvement
in results (F1: 0.520 –&gt; 0.550, accuracy: 0.56 –&gt; 0.62 for GPT-4 Turbo and F1: 0.382 –&gt; 0.394, accuracy:
0.52 –&gt; 0.55 for GPT-4o mini). Interestingly, instructional prompts that encouraged structured reasoning
or numerical focus did not consistently improve accuracy, and in some cases (e.g., Focus Numerical)
reduced it. GPT-4 Turbo outperformed GPT-4o mini, likely due to Turbo being a larger model that was
thus able to better leverage few-shot examples.</p>
      </sec>
      <sec id="sec-4-2">
        <title>4.2. Confidence Rating with GPT-4</title>
        <p>To understand whether state-of-the-art powerful LLMs with reasoning capabilities have an
understanding of their own corectness, we evaluated how efective confidence self-ratings were for GPT-4, looking
specifically at how results changed as confidence ratings increased. The macro average F1 scores on
only samples for which the model gave a self-confidence ranking of at least X (where X went from 1 to
5) are shown in Figure 2.</p>
        <p>These results show that except for the increase in confidence from 1 to 2, performance consistently
increased as model confidence increased. Consistent increases in F1 score can be seen between the
subset of the data for which the model gave a self-confidence ranking of 2 to 5. Overall, the F1 scores
increased over 25%, going from 0.411 on the entire dataset (confidence rankings ≥ 1) to 0.524 on only
the examples for which the confidence ranking was 5 showing that model self-confidence is a strong
indication of higher performance.</p>
        <p>The results from the logistic regression model trained to predict accuracy from confidences are shown
in [Table 3]. The coeficient on the confidence predictor was 0.3171, showing a moderately strong
positive relationship indicating that as model confidence increases, the prediction is more likely to be
correct. The p-value (0.0410) &lt; 0.05, showing that the confidence does have statistically significant
predictive power over the accuracy of predictions.</p>
        <p>GPT-4 Macro Avg F1 Scores and Accuracy across Prompt Variations
Prompt Variation
Baseline Prompt
(1) 10 Examples</p>
        <p>Prompt text
[baseline prompt] + [few shot examples: 2 examples from every
class]
[baseline prompt] + [few shot examples: 10 examples from every
class]
(2) Focus Numeri- [baseline prompt] + When you are evaluating the claims please
cal focus on the NUMERICAL aspects of the claim (i.e., are the
numerical parts of the claim correct based on the evidence) rather
than other aspects of the claim + [few shot examples: 2 examples
from every class]
(3) Focus Claim
Decomp
[baseline prompt] + When you are evaluating the claims, note
that the claims often have several parts and at least one numerical
part. Break down the claim into all its parts, evaluate each one
and if there is a numerical part of the claim focus on the numbers
in the claim and evidences + [few shot examples: 2 examples from
every class]
(4) Annotated Ex- [baseline prompt] + [few shot examples: 2 examples from every
amples class with each example including a human-created annotation</p>
        <p>explaining the reason it was classified as its label]
(5) Baseline + Rea- [baseline prompt] + [few shot examples: 2 examples from every
soning class] (prediction generated with GPT-4o-mini)
(6) 10 Examples +
Reasoning
[baseline prompt] + [few shot examples: 10 examples from every
class] (prediction generated with GPT-4o-mini)
F1</p>
        <p>Overall, the results from the confidence self-ratings analysis show that confidence is indicative of
performance and that on samples where the model reports a higher confidence, it is more likely to be
correct. These results support the use of confidence self-ratings as a decider in a voting mechanism
between GPT-4 and fine-tuned Llama 2 in our ensemble.</p>
      </sec>
      <sec id="sec-4-3">
        <title>4.3. Ensemble Results</title>
        <p>As described in section 3.1 and 3.5, the final ensemble combined the individually optimized models
(fine-tuned Llama and GPT-4 with few-shot prompting) via a voting mechanism. The Llama model
used in the final ensemble was fine-tuned on all available train and validation data. For GPT-4, the
prompt variation with the highest performance was the baseline prompt with more examples per class
included in the few-shot examples (run on GPT-4 Turbo) [Table 2]. Thus, we used this prompt variation
for the GPT-4 model in the final ensemble. However, we did make one change to the prompt, namely
changing the number of examples from 10 to 3 to reduce token counts for API calls while still gaining
the advantages of more examples per class in the prompt. The voting mechanism we used in the
ensemble set the self-confidence rating threshold to 5 (i.e., disagreements were only decided in favor of
GPT when the self-confidence rating was 5). Due to the large gap observed between performance with
thresholds of 4 and 5 in testing [Figure 2], this ensured that GPT only acted as a decider when it had
high confidence and thus was also the most likely to be correct.</p>
        <p>Task 3 Evaluation Results: The results of our ensemble approach on the test set are shown in
Table 4. The final Macro average F1 score of the ensemble was 0.4857. The ensemble performed the best
on False examples with a False F1 score of 0.7820. The True F1 score was slightly lower (0.5090) and the
models struggled the most with the Conflicting class, with the Conflicting F1 score being significantly
lower, 0.1661. These results show that the ensemble observed the same efect as the fine-tuned Llama
model alone with better performance on False examples than on True and Conflicting , likely reflecting
the higher proportion of False examples in the datasets. While the overall performance was moderate,
placing 7th on the leaderboard, the results suggest that the ensemble was a reasonably efective strategy,
especially for handling clearer cases with high model confidence.</p>
        <p>The performances, both F1 score (macro average F1) and accuracy (count correct / total count) of
the ensemble method and each method individually are shown in Table 5. Note that the Llama results
are only computed over the subset of total test set examples for which we produced Llama predictions
on the test set (i.e., examples for which GPT did not give a self-confidence rating of 5) as described in
section 3.5. Note that for 33 examples on which GPT-4 gave a self-confidence rating of &lt; 5, the Llama
model failed to produce an outputted label so the final prediction was set to the GPT prediction. These
33 examples are thus also not included in the calculation of Llama individual results.</p>
        <p>These results show that the ensemble method and GPT-4 performed similarly, with the ensemble
out-performing GPT-4 in terms of accuracy. Ensemble accuracy (0.6601) was higher than both GPT-4
accuracy (0.6556) and Llama 2 accuracy (0.4815) and the ensemble F1 score (0.4948) was slightly lower
than the GPT-4 F1 score (0.5035) and greater than Llama 2 (0.4368). As the majority of the predictions
in the test set had a confidence rating of 5, GPT-4 performance was close to ensemble performance.
The overall ensemble still had a higher accuracy than both models individually, showing that ensemble
based on self-confidence ratings can efectively leverage the complementary strengths of both models.</p>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>5. Discussion and Conclusions</title>
      <p>In this task we investigated using an ensemble approach to combine predictions of two LLMs: Llama
2-7B fine-tuned on training and validation data and GPT-4 with few-shot prompting. We developed a
voting mechanism based on self-confidence rankings reported by GPT. This confidence-based voting
helped to mitigate errors without requiring additional models or complex calibration schemes.</p>
      <p>The results showed that the ensemble model approach was moderately efective, achieving a Macro
Average F1 score of 0.4857 on the test set in evaluation. We found that the ensemble performed
particularly well on False examples and performed competitively on True examples, placing 3rd in the
leader board for True F1. The model struggled the most with Conflicting data likely due to the less clear
nature of these claims and its lower representation in training and validation datasets. This suggests
that further approaches would be needed to improve the performance of both models, especially on
the more confusing Conflicting claims. These results suggest that other approaches, particularly those
incorporating explicit reasoning may be helpful to improve performance on claims that are ambiguous
or confusing.</p>
      <p>We also explored using a numerically-focused model trained on the FinQA dataset to improve
performance on complex numerical claims. This approach involved experimenting with various input formats,
including selectively incorporating gold evidence—annotated text spans from financial documents that
ideally support the answer. We tested strategies like conditional inclusion of gold evidence only when
the model previously answered incorrectly, aiming to guide learning without overfitting. Additionally,
we attempted to ensemble this numerical model with a general-purpose model like Llama using majority
voting. However, despite these eforts, accuracy improvements were minimal and did not meaningfully
outperform the baseline.</p>
      <p>We conducted an analysis on reported self-confidence for numerical claim verification and found
that higher reported self-confidence did indicate higher likelihood of correctness and higher accuracy.
Thus, we showed that for the task of numerical claim verification, state-of-the-art LLMs have the ability
to judge their own predictions and report accurate confidences in these predictions.</p>
      <p>Our evaluation also demonstrated that the ensemble method we developed had a higher accuracy than
each constituent model individually on the test set. We show that integrating models via self-confidence
rankings can lead to performance improvements. These results highlight the value of combining
highconfidence predictions from large general-purpose models such as GPT-4 with specialized models like
ifne-tuned Llama 2 on examples where confidence is lower. This approach can be especially valuable in
domains such as numerical claim verification where errors are common and can be dificult to detect.</p>
      <p>Overall, we showed that in the context of numerical-claim verification, LLMs are capable of
introspective reliability estimation, producing self-confidence ratings that are indicative of model performance.
By leveraging these confidence ratings in combination with a fine-tuned Llama model, we show that
LLM-based verification systems can be made more robust for factual reasoning tasks.</p>
    </sec>
    <sec id="sec-6">
      <title>Declaration on Generative AI</title>
      <p>The authors have not employed any Generative AI tools.
New York, NY, USA, 2024, pp. 650–660. URL: https://doi.org/10.1145/3626772.3657874. doi:10.
1145/3626772.3657874.
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