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    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Information Extraction to Support Automation of Navigation through 3D Models during Collaborative Design Sessions</article-title>
      </title-group>
      <contrib-group>
        <aff id="aff0">
          <label>0</label>
          <institution>Lucian Constantin Ungureanu, Timo Hartmann Technical University of Berlin</institution>
          ,
          <country country="DE">Germany</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>This paper explores the possibility of creating a voice-based interface to support collaborative design sessions. The main purpose is to automate changes of viewpoints for 3D models based on ongoing design conversations. We employ a design science research methodology and propose a framework to support this task. Within the structure of the framework, we propose three main components for (1) information filtering, (2) information extraction and (3) domain knowledge encapsulation. A small-scale implementation on two transcripts of real-world design sessions allows us to assess the performance of the components. The classifier for information filtering performs well for identifying the speaker turns not related to viewpoint changes of the 3D model, while additional work needs to be done to reduce the rate of false positives. It also reveals various future research directions.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        During such sessions, creativity is enhanced by using various design artefacts. Designers
interact with design artefacts and use these to support communication
        <xref ref-type="bibr" rid="ref19">(Perry and Sanderson,
1998)</xref>
        . Examples of such artefacts are drawings, sketches, and virtual representations such as
3D models
        <xref ref-type="bibr" rid="ref19">(Perry and Sanderson, 1998)</xref>
        . Most of these artefacts represent visual aids. These
visualizations are meant to enhance communication, coordination and collaboration
        <xref ref-type="bibr" rid="ref15 ref7">(Leite et
al., 2016; Dossik and Neff, 2011)</xref>
        . Computers started to play an essential role during such
sessions, especially considering the high adoption rate of building information modelling
        <xref ref-type="bibr" rid="ref9">(Golparvar-Fard et al.,2013)</xref>
        . The use of 3D models to support collaboration and
communication has been widely adopted. For example, a survey conducted in the U.S.
        <xref ref-type="bibr" rid="ref15">(Leite
et al., 2016)</xref>
        reported that 3D models represent the most commonly used form of visualization,
with a score of 95%. Moreover, technological tools are supposed to “stimulate, cause or assist”
creativity
        <xref ref-type="bibr" rid="ref1">(Achten and Beetz, 2009)</xref>
        . A review of collaborative design studies
        <xref ref-type="bibr" rid="ref1">(Achten and Beetz,
2009)</xref>
        reported that 40% of the studies focus on technological aspects, a conclusion also
enforced by later studies
        <xref ref-type="bibr" rid="ref7">(Dossik and Neff, 2011)</xref>
        . At the same time, the static nature of 3D
representations does not allow for a natural interaction with the virtual artefacts
        <xref ref-type="bibr" rid="ref7">(Dossik and
Neff, 2011)</xref>
        .
      </p>
      <p>
        In practical settings, designers expect to be able to points to (gesture), talk about (speech) or
sketch on (sketching)
        <xref ref-type="bibr" rid="ref19">(Perry and Sanderson, 1998)</xref>
        . When it comes to gesture and sketching,
emerging technologies such as touch-based hardware are possible alternatives towards a more
natural designer-artefact interface. Various studies
        <xref ref-type="bibr" rid="ref10 ref12 ref13">(Kim and Maher, 2008; Gu et al., 2011)</xref>
        started investigating the effect of tangible interfaces on design creativity. A study comparing
gesture-based communication with sketching-based communication
        <xref ref-type="bibr" rid="ref8">(Eris et al., 2014)</xref>
        highlight
that speech is the main communication channel, while gesture and sketching represent
secondary means of communication. To our knowledge, speech-augmented designer-artefact
interaction does not currently represent a mature research area.
      </p>
      <p>This paper investigates the possibility to automatically extract information from design
communications to automatically change viewpoints in 3D models. During design sessions,
participants naturally communicate their ideas, intentionally referring to some detail of the
design. However, navigating a 3D model to find a viewpoint that shows this detail is a tedious
task. Moreover, most of the times, participants in such sessions do not have the required skill
set to quickly change a 3D model’s viewpoint. A natural language interface between
participants and computer might represent a good alternative. However, contemporary voice
assistants are intrusive as they require formalised queries.</p>
      <p>In this study, we are looking at automating the extraction of viewpoints-related information out
of natural human-to-human conversations. To this end, we propose a framework which
combines ontological modelling of domain-specific knowledge and the use of probabilistic
models to support information filtering and extraction from natural language conversations.
The paper continues with a more detailed overview of state-of-the-art possibilities to interact
with digital design artefacts. The paper then introduces the steps we followed to conduct this
research as well as the framework we proposed to solve the problem of automatically changing
the viewpoints of 3D models. Moreover, we present the implementation of the proposed
framework using the transcripts of two real-world design meetings. The implementation is
followed by the evaluation of various parts of the framework and discussions of the current
status of the framework, where we propose various scenarios for future development. Finally,
we present a summary of our findings, limitations and future research in the conclusion section.</p>
    </sec>
    <sec id="sec-2">
      <title>2. Human-Computer Interfaces in Design</title>
      <p>
        Human-Computer interfaces usually require a set of input and output devices. Input devices
allow a user to provide a set of commands which are translated in specific machine-interpretable
actions. The user accesses the results of the provided commands using output devices.
Keyboard and mouse represent the most common input devices, while screens represent the
most common output devices. Early research in the field of computer-aided design aimed to
assess the human performance while using machines for design tasks
        <xref ref-type="bibr" rid="ref5">(Cuomo and Sharif, 1989)</xref>
        emphasising the need of training to improve the human performance, while more recent
research start focusing on the need of designing better interfaces aiming at a more natural and
intuitive way of interacting with machines
        <xref ref-type="bibr" rid="ref21">(Turk, 2014)</xref>
        .
      </p>
      <p>
        To this end, the research community highlighted that multi-modality is an inherent
characteristic of human communication
        <xref ref-type="bibr" rid="ref21">(Turk, 2014)</xref>
        . Aiming to move away from the
keyboard-mouse-based input interface, the research community started exploring various
interfaces which will allow the humans to provide input through gesture, sketching and
speaking. When it comes to design, the purpose is to allow the computers to meaningfully
support the design process without hindering creativity.
      </p>
      <p>
        On one hand, as a result of the rapid technological development, gesture and sketch-enable
technologies are slowly integrated into the design process. Studies show that these tangible
interfaces increase creativity
        <xref ref-type="bibr" rid="ref10 ref12 ref13">(Kim and Maher, 2008; Gu et al., 2011)</xref>
        . On the other hand, there
is a huge gap in the use of speech-based interfaces during collaborative design sessions. Most
of the previous research focused on developing voice-based input interfaces with a limited
number of voice-based commands which allow users to access various CAD-software
functionality such as modelling geometrical primitives
        <xref ref-type="bibr" rid="ref12 ref13 ref14 ref22 ref23 ref4">(Chu et al., 1997; Kou and Tan, 2008;
Xue et al., 2009; Kou et al., 2010)</xref>
        or accessing information linked to 3D elements
        <xref ref-type="bibr" rid="ref14 ref2 ref23">(Xue et al.,
2010, Behera and McKay, 2017)</xref>
        . A limitation of the proposed systems is that users always need
to remember what they can ask the computer. Additionally, expanding the repository of
available commands is very difficult. Finally, these commands are highly structured and disrupt
the natural course of design conversations. Advanced approaches which make use of the current
state of the art natural language techniques are still missing, but moreover, there is a lack of
understanding the specificity of the natural language conversations used in design-related
situations. This paper employs a design science research method which aims at laying the
foundation for the development of non-intrusive voice-based interfaces, with the main goal of
changing the 3D models’ viewpoints based on information extracted out of natural language
conversations held by the practitioners during collaborative and coordinative sessions.
      </p>
    </sec>
    <sec id="sec-3">
      <title>3. Research Method and Framework Description</title>
      <p>
        This paper employs a design science research method following the framework proposed by
        <xref ref-type="bibr" rid="ref18">Peffer et al. (2007)</xref>
        . Figure 1 presents the problem-centered research method which consists of
five main components. Extracting the right information of out human-to-human conversations
is a challenging task mainly because there is no distinction between commands-related
conversation and background conversation (messy talk). The objective of the current paper is
to develop a system that will extract the information related to various parts of the product to
be designed and perform operations such as zoom in or isolate the parts mentioned by designers.
For example, when designers exchange design ideas about the first floor, the operation expected
from the system is to isolate the first floor as shown in Figure 2.
Figure 3 presents the proposed framework. Within this framework, we distinguish three major
components, namely: (1) information filtering, (2) information extraction, and (3) domain
knowledge base. Information filtering represents the process of removing data from an
incoming stream with the sole purpose of keeping the information relevant for a task (Belkin
and Croft, 1992). Information retrieval represents the process of extracting the information
required to perform a task. Both, information filtering and information retrieval are contexts
sensitive. In our framework, this gap is addressed using the third component – domain
knowledge.
To develop this system, we use a dataset of recordings of design conversations. We aim at
extracting specific information for viewpoint changes for this dataset. As design conversations
are unstructured, we structure the cleaning process in two subtasks: (1) automatic detection of
those utterances and natural language constructs not related to viewpoints changes and (2) a
manual cleaning necessary as preparation for the information extraction. For the automatic
detection of task-related constructs, we explore the use of probabilistic classifiers. A classifier
can identify constructs not related to any viewpoint operations and discard these. To support
information filtering and information extraction, we built an ontology. This ontology aims to
capture the knowledge related to the project breakdown. The central assumption we make is
that participants use domain-specific named concepts during conversations. We use the error
rate to individually evaluate the proposed components for information filtering and information
extraction to conduct an end-to-end validation of the entire framework.
For a small-scale practical implementation of the framework, we used the transcripts of two
architectural meetings recorded by the Design Thinking Research Group (Llyod et al. 2005).
These meetings are part of an effort to design a crematorium and were recorded in their natural
setup. Both meetings combined consist of 2318 speaker turns and almost four hours of recorded
time. Three participants were involved during the first meeting (A1) and five participants for
the second meeting (A2). In both meetings, a researcher was present as an observer. During the
design sessions, participants focus on designing various parts of the crematorium while using
paper-based drawing to visualize various parts of the design. At this point, it is worth
mentioning that no computer-based artefacts were used during these sessions. In this paper, we
address the issue of information filtering and information extraction supported by an ontology
created for the crematorium domain.
Figure 4 presents the crematorium-related domain concepts included in the ontology. The
ontology has concepts functional parts (which include concepts such as waiting room or chapel
which describe the functional aspects of a crematorium project), components (which included
concepts such as wall or roof), locations (which include concepts such as back or top), and
materials (which include concepts such as concrete). These concepts were used to automatically
label speaker turns which contain these concepts. For the information filtering, we prepared the
transcripts for a binary classification problem, where a new feature was created to indicate if a
specific speaker turn is or is not a possible candidate for a viewpoint change, mainly based on
content related to the ontological concepts. After labelling 541 speaker turns were labelled as
related, while 1777 were labelled as not related. In preparation for the classification, we
performed additional cleaning tasks such as remove numbers, stop words, and punctuation,
steaming and characters case folding from upper to lower case. After cleaning, a document term
matrix was created. In a document-term matrix, the number of rows is equal to the number of
documents while the number of columns is equal to the number of unique terms in the dataset.
For our implementation, the number of rows is equal to the number of turns (2318) and the
number of columns corresponds to 2224 unique terms. Each term is weighted based on its
frequency on each turn. For the classification, 75% of the dataset was used for training and the
other 25% were used for testing. Within the training subset, 1320 turns correspond to negative
class and 418 turns correspond to the positive class. Within the testing subset, 457 turns
correspond to negative class and 123 turns correspond to the positive class. We implemented a
simple Naïve Bayesian classifier for which we disabled the Laplace smoothing (Laplace = 0).
For the information extraction, we implemented a natural language parser and we extracted the
noun phrases (NP) from each turn. These phrases were once again filtered, using pattern
matching to keep only those which are part of the crematorium ontology. The performance of
the information filtering module depends on the language used during design and on the
concepts captured in the ontology. When it comes to language use, one of the major concerns
relates to syntactic ambiguity. Syntactic ambiguity means that a sentence can have more than
one parse trees, which means that some parts can have multiple syntactic roles within the uttered
sentence. As mentioned previously, those concepts captured in the ontology must reflect the
structure of the design artefact (e.g. 3D models). For an in-depth analysis, we can consider the
following sentence extracted from the transcripts.
“Basically we're arriving in the new car park in this area and from the car park we'll enter the
building through a waiting area”.
      </p>
      <p>The syntactic parser identifies the following items as noun phrases: "we", "the new car park"
"this area", "the car park", "we", "the building", "a waiting area". Using the concepts included
in the ontology, the following terms are extracted after filtering: “building”, “waiting area”,
“car park”. We notice that the quantifier “new” used by the speaker to make a separation
between the existing car park and the new car park is missing.</p>
    </sec>
    <sec id="sec-4">
      <title>4. Evaluation and Discussions</title>
      <p>The results of the classifier indicate a sensitivity of 53.91% and a specificity of 94.42%, with a
balanced accuracy of 74.16%. The classifier performs well in terms of identifying those turns
not related to viewpoint changes. The true positive rate is low, and future efforts should focus
on improving this and reducing the false positive rate as these correspond to turns related to
viewpoint changes. Moreover, one limitation of the current exploration is given by structuring
the conversations on speaker turns. This approach does not capture the real behaviour of the
speaker. Segmentation of the speaker turns in small units called utterances must be employed
in this direction. Moreover, experimentation with other classification methods should be the
subject of future studies, especially with those which perform well on short text classification.
The use of natural language processing techniques, such as parts of speech tagging and syntactic
parsing, is usually computationally intensive. In this direction, the use of the classifier to discard
the turns not related to viewpoints helped to reduce the workload for a such as task. For an
utterance such as “basically we're arriving in the new car park in this area and from the car
park we'll enter the building through a waiting area” the extracted parts will be [“car park”,
“car park”, “building”, “waiting area”]. “car park” and “waiting area” represent specific parts
which can be easily identified, and the system can perform operations such as isolating or
zooming in. When it comes to the concept “building” it is not clear to what building the speaker
refers to. A limitation of this study is that it is not considering the relationships defined in the
ontology. A relationship such as “crematorium” has some “waiting room”, “waiting room” has
some “wall”, “wall” has some “window” will allow us to identify when the speaker refers to
“that specific window which is part of the wall which is part of the waiting room”, and not to
another window.</p>
      <p>Ontologies also play an important role in improving the performance of the voice assistants
such as Alexa or Siri. Most of the voice assistants make use of WikiData repository which is
mainly built for general purpose tasks. Design is a very specialized activity for which
repositories such as WikiData do not manage to capture all required knowledge.
One major limitation of both components proposed for information filtering and information
extraction is that it covers only those situations where the speaker directly refers to the thing,
without considering that the speaker might refer to a thing using various expressions such as
“this” or “it”. Future studies will aim to investigate the use of coreferential expressions in
design conversations. Moreover, future efforts will focus on creating an instantiation of the
proposed artefact for the purpose of end-to-end testing. Moreover, any operation leading to the
change of viewpoints in 3D models need to clearly identify the input data required to be
performed. Making the operation indicated in Figure 2 requires additional domain knowledge
such as knowing which elements are part of level 1. This points out toward the fact that the
ontology needs also to capture knowledge related to the semantic hierarchy of the 3D models.</p>
    </sec>
    <sec id="sec-5">
      <title>5. Conclusions</title>
      <p>The current paper proposes an artefact which aims to address the gap of voice-based interfaces
in collaborative design sessions. This research follows the design science methodology with the
aim of creating a framework to solve the above-stated problem. Precisely, the framework aims
to analyse the participants’ conversations with the purpose of filtering and extracting
information related to the viewpoints of the 3D models. For the filtering task, we proposed the
use of a classifier, while information extraction relies on natural language processing techniques
such as syntactic parsing.</p>
      <p>A small-scale implementation was performed using the transcript of two real-world design
sessions. The design science research method proposes an iterative approach to develop the
framework. Each iteration reveals various aspects which need to be addressed by future
research. In the case of our implementation, the classifier proposed for information filtering
performs well for the classification of the true negatives (turns not related to 3D models’
viewpoints). The performance of the classifier on true positives indicates that future research
should focus on reducing the false positives, aim to capture the real speakers’ behaviour by
segmentation of the transcript in small utterances, and exploring the performance of various
classification methods especially focusing on short text classification. Implementation of the
information extraction module indicates that future research should focus on making better use
of the knowledge encapsulated in the ontologies.</p>
    </sec>
  </body>
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