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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>TrackThink Camera: A Tool for Tracking Facial and Body Information while Web Browsing</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Ko Watanabe</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Seiya Tanaka</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Andrew Vargo</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Koichi Kise</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Shoya Ishimaru</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>DFKI GmbH</institution>
          ,
          <addr-line>Tripstadter 122, 67663 Kaiserslautern</addr-line>
          ,
          <country country="DE">Germany</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Osaka Metropolitan University</institution>
          ,
          <addr-line>1-1 Gakuen-cho, Naka, Sakai, Osaka 599-8531</addr-line>
          ,
          <country country="JP">Japan</country>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>RPTU Kaiserslautern-Landau</institution>
          ,
          <addr-line>Pfafenbergstrasse 95, 67663 Kaiserslautern</addr-line>
          ,
          <country country="DE">Germany</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>In a world where the amount of information is increasing daily, estimating cognitive and afective states in web search activity is essential for self-management. Previous studies have investigated methods for collecting logs of web search activity, such as URLs of web pages visited, tab activation, and clipboard copying. However, none of the work focuses on external information, such as collecting the person's facial expressions or body movements while searching. In this paper, we extend the existing system to enable synchronous collection of web search logs and web camera recordings. Through this research and development, we aim to analyze the cognitive and afective states during search behavior and help improve the eficiency of web search. Our new software will be available to anyone with research purposes.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;thought process</kwd>
        <kwd>browsing behavior</kwd>
        <kwd>web search</kwd>
        <kwd>cognitive metrics</kwd>
        <kwd>camera as a smart sensor</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        Web search is an essential part of our daily lives. It supports our productivity, creativity,
recreation, and even socialization. Previous studies have proposed tools for collecting or
visualizing web search logs [
        <xref ref-type="bibr" rid="ref1 ref2 ref3">1, 2, 3</xref>
        ]. These approaches successfully understand users’ search
activity within a computer or web browser. A study by Aula et al. found that most people,
novices and experts alike, produce a certain body language when they get stuck in a search [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ].
Their research then turned to detecting frustration, or so-called behavioral changes, from the
activity inside the computer. However, we can better understand their cognitive/afective states
by synchronously capturing their frustration directly from webcam recordings. Therefore, the
discovery of cognitive/afective states from web camera browsing is fascinating.
      </p>
      <p>
        Estimating cognitive/afective states is a crucial variable afecting human performance in
various tasks, including puzzle solving, scuba diving, public speaking, education, fighter aircraft
operation, and driving [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]. Understanding the cognitive/afective state during exploration helps
Web Browsing Logger TrackThink[
        <xref ref-type="bibr" rid="ref11">11</xref>
        ]
      </p>
      <p>Ours</p>
      <p>
        Fridman et al.[
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]
      </p>
      <p>Cognitive State Estimation
by Facial and Body Image
SearchBar[12]</p>
      <p>
        Grimmer et al.[
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]
us understand how eficient our performance was in finding solutions. The concept of estimating
cognitive load in the wild, or Automatic Emotion Recognition (AER) technologies [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ], needs to
gain attention in research and industry. There is work on estimating the afective state while
using a smartphone in the wild [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ]. This system lets users get feedback on afective states while
using the phone. One of the core techniques for understanding cognitive/afective states is
using facial or body information [
        <xref ref-type="bibr" rid="ref10 ref8 ref9">8, 9, 10</xref>
        ].
      </p>
      <p>
        Determining cognitive states while reading digital textbooks has been done by several
researchers [
        <xref ref-type="bibr" rid="ref11">11, 12</xref>
        ]. The approaches mainly use an eye tracker or a heat sensor to estimate
cognitive states. Previous research has found that body temperature and blink frequency best
estimate engagement and can classify users independently as engaged or disengaged [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ].
Researchers have also found that pupil diameter and nasal temperature changes correlate with
cognitive state [12]. These studies contribute to the understanding of cognitive states during
reading in particular. However, all of these researches use additional sensors to detect cognitive
states. In addition, these studies focused on something other than reading activity during a web
search.
      </p>
      <p>
        This paper proposes a system that synchronously uses a web camera to collect web search
behavior logs and camera-recorded facial and body information. At the same time, a user
performs a web search. Figure 1 shows the intersection of previous work in the Venn diagram. Our
position is to implement an all-in-one technology for tracking web search behavior and
synchronizing web camera recordings. The system extends the web search logger TrackThinkTS [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ].
This system works with the Google Chrome extension. It does not require any additional
sensors or hardware devices. Our main contribution is that we can obtain cognitive/afective
information from the user’s facial and bodily behaviors without sacrificing this feature. Instead
of installing additional sensors or a system to log the video information, anyone can use the
system just by installing the Google Chrome extension in the web browser. To the best of our
knowledge, we are the first to research and develop an all-in-one system to collect web searches
and facial and body behaviors.
      </p>
    </sec>
    <sec id="sec-2">
      <title>2. Related Work</title>
      <p>In this section, we focus on three key areas of literature: (1) prior work on web search loggers,
(2) prior work on cognitive/afective state estimation by facial and body information, and (3)
prior work on cognitive/afective state estimation during a web search. Understanding the
related work highlights the significance of discovering facial and body movements while web
browsing.</p>
      <sec id="sec-2-1">
        <title>2.1. Web Search Logger</title>
        <p>
          Web search logger is a topic that has been gaining interest in Human-Computer Interaction
(HCI), with most studies focusing on discovering the thought process. Morris et al. has proposed
a search-centric web history logger SearchBar [
          <xref ref-type="bibr" rid="ref2">2</xref>
          ]. SearchBar is a system implemented as a
plugin for Internet Explorer. The system can retrieve, store, and present an annotated integrated
search history. Over time, the search history collection will be extended to the mobile scene.
Kamvar and Baluja worked in the field of mobile [ 13]. They used the XHTML search interface
to collect and set the experimental condition to analyze the web search behavior. Nagano et al.
proposed the concept of TrackThink, a system for tracking human thought processes from
web search logs [14]. This system is then extended by Makhlouf et al. and becomes publicly
available for anyone to use as a Google Chrome extension [
          <xref ref-type="bibr" rid="ref3">3</xref>
          ]. Carrasco et al. has proposed a
popHistory system that collects web search history and visualizes it in a bubble interface [
          <xref ref-type="bibr" rid="ref1">1</xref>
          ].
It can segment the result into a specific time range. In conclusion, according to our survey,
none of the previous web search behavior loggers used a web camera to record data outside the
computer.
        </p>
      </sec>
      <sec id="sec-2-2">
        <title>2.2. Cognitive/Afective State Estimation from Facial and Body Information</title>
        <p>
          Various approaches have been used for cognitive/afective state estimation. This section focuses
on camera-based or facial image-based cognitive state estimation. Kunze et al. works on
estimating the level of engagement during reading using a Tobii eye tracker and temperature
sensors attached to the nose and ear. They found that temperature and blink frequency are
the best ways to estimate the engagement and can classify engaged and disengaged users
independently. Fridman et al. proposed a system to estimate cognitive load in the wild by a
camera while driving a car [
          <xref ref-type="bibr" rid="ref5">5</xref>
          ]. Their approach is to extract discriminative signals in the eye
movement dynamics to detect the level of cognitive load. Using the 3D-CNN approach, they
achieved 86.1% on 3-class cognitive load estimation. Grimmer et al. also used pupil information
to estimate cognitive load. They found that pupil diameter decreased over time during the
control condition and the 1-back task. However, they also mentioned that the diferences in
pupil diameter remained the same between the 2- and 3-back tasks. Watanabe et al. proposed
engagement level estimation in remote communication [
          <xref ref-type="bibr" rid="ref9">9</xref>
          ]. With respect to these works, facial
and body information play an important role in understanding human cognitive and afective
states.
        </p>
        <p>Landing Page
Stop Recording</p>
        <p>Export CSV and WebM</p>
      </sec>
      <sec id="sec-2-3">
        <title>2.3. Cognitive/Afective State Estimation during Web Search</title>
        <p>
          Whether novice or expert, searchers need help finding the information they want. Aula et al.
have discovered that when searchers are frustrated, there are observable changes in their
behavior [
          <xref ref-type="bibr" rid="ref4">4</xref>
          ]. Specifically, their body language changes (e.g., they frown, start biting their nails,
and many lean closer to the screen to ensure they are not missing something obvious), and
they begin to sigh. In read-aloud studies, they tend to forget to read aloud. These actions can
trigger an estimation of which website they have been frustrated or struggled with during web
searches.
        </p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3. System Overview</title>
      <p>
        This study will use TrackThinkTS [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ] as a baseline system. It collects various information
about web search behavior. In this section, we will explain the baseline system in detail. Then
we explain two new specific functions: a recording segmentation function and a web camera
recording function. The new system TrackThink Camera operation flow is presented in Figure 2.
      </p>
      <sec id="sec-3-1">
        <title>3.1. TrackThinkTS: Baseline System</title>
        <p>
          Makhlouf et al. proposed TrackThinkTS as a privacy-aware browsing log tracker. It monitors
the following browsing actions and collects logs [
          <xref ref-type="bibr" rid="ref3">3</xref>
          ]. First, it collects information about the
visited website (a website title, URL, HTML content, viewport width/height, and document
width/height). Each time a tab-related operation occurs, such as creating a tab, launching a tab,
reloading a tab, or deleting a tab, the system keeps a log. Second, specific user actions while
browsing the website are collected, such as scrolling logs (scrolling speed, scrolling length, and
visible text after scrolling is finished) and clipboard logs (the clipboard contents). Compared to
typical browsing history, it is possible to collect information such as which parts of the page
the user looked at in detail and how long they stayed on each page. Another advantage of
TrackThinkTS over other browser loggers is its user-friendly interface for filtering each log.
Therefore, study participants using TrackThinkTS can delete privacy-sensitive information
before submitting their log files to an experimenter.
        </p>
      </sec>
      <sec id="sec-3-2">
        <title>3.2. Recording Segmentation Function</title>
        <p>The traditional TrackThinkTS system collects web activity logs after the extension is installed.
Logs are collected continuously until the CSV file is downloaded. Therefore, the existing
system records web activity immediately after installation by the user. To avoid privacy issues
from collecting all logs, TrackThinkTS can delete logs before exporting data. In this work,
we implement the start and stop buttons to handle the beginning and end of data collection.
Therefore, we added a start/stop recording feature to allow users to record web activity data
selectively. More precisely, we placed a recording button on the Settings tab of the extension to
manage the start and stop.</p>
      </sec>
      <sec id="sec-3-3">
        <title>3.3. Web Camera Recording Function</title>
        <p>This section explains the Web camera recording function. Figure 2 shows an overview of the
system. Each person follows the operation as shown below.</p>
        <p>1. Start Recording - Click Turn on Camera and Start Recording buttons for logging.
2. Allow Recording - Click Allow button for giving permission for camera recordings.
3. Stop Recording - Click Stop Recording button to stop logging.
4. Download Logs - Click Download the logs and video button to download files.
5. Restart Recording - Click Start Recording and logs will be refreshed once.</p>
        <p>The new TrackThink Camera allows users to record facial and body recordings using the
web camera. Users can also check storage the storage of video recordings while logging. The
video can be downloaded locally in WebM format, and a web search logs in CSV. The WebM file
name will be generated based on the user ID, name, and recording end time.</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>4. Discussion &amp; Limitations</title>
      <p>
        This paper proposes a new system that synchronously collects search behavior logs and facial
and body recordings. The system can now control the start and end of data collection and store
video recordings. When we conducted a pilot study, we discovered that participants looked
closer at the screen when they found the page dificult to understand, as mentioned in the
previous paper [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. For the next step, some limitations need to be covered.
      </p>
      <p>First, we did not perform a validation experiment with multiple users. We confirmed that
the system works well in collecting web search behavior and video recording. However, we
did not collect data on cognitive activity during browsing. Experimental design will also be a
topic of discussion when conducting a validation experiment. It is necessary to determine how
to design tasks with diferent cognitive loads during the search. Discussing the collection of
multiple cognitive states in the search activity would be desirable.</p>
      <p>Second, in this system, the challenges observed from our prototype implementations are
the highlighting function. In order to select facial and body images while viewing each web
page, it is necessary to refer to the time stamps collected in the search logs. Specifically, it is
necessary to determine the starting position of the video when viewing a particular page using
the timestamp at the start of data collection and the timestamp at the time the web page is
viewed. Creating highlights when downloading and adding them to the output video would be
desirable.</p>
      <p>Lastly, regarding the earlier question, another challenge is to cut out sensitive scenes from
the recordings. There are functions for deleting the search log data, but the video recordings are
not trimmed before downloading. When implementing the highlight functions, it is necessary
to make the video trimming function allow deleting the facial and body shots while viewing
the personal website.</p>
    </sec>
    <sec id="sec-5">
      <title>5. Future Work</title>
      <p>In our future work, we want to implement some systems using the TrackThink Camera. One
of the ideas is to use appearance-based eye-tracking techniques. We are interested in adding
this technology to identify what part of the web page the person was looking at within the
web content. This approach will further support understanding the cognitive status of where
specifically the user was looking within the web page. Another idea is to quantify the cognitive
load of the web page. By doing so, people can choose to read the web page according to
the enumerated cognitive load information of the web page. Considering GDPR (General
Data Protection Regulation), our future work includes secureness on privacy issues. We will
implement additional options for exporting data, such as allowing to export of cognitive load
estimation results only. Finally, we would also like to create a dashboard for web searchers to
retrieve cognitive lifelog data. This way, users can understand which web pages have a high
cognitive load. These features will significantly benefit all web search users in the future.</p>
    </sec>
    <sec id="sec-6">
      <title>6. Conclusion</title>
      <p>This paper proposes a Google Chrome extension tool, TrackThink Camera, to collect web search
activity and facial/body behavior logs. This system supports collecting web search activity and
facial/body video recording. Our proposal is the first to collect internal and external information
about people while working on web search activity. The new software will be available to
anyone with research purposes.</p>
    </sec>
    <sec id="sec-7">
      <title>Acknowledgments</title>
      <p>This work was supported in part by JST Trilateral AI Research (JPMJCR20G3).
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