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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Adaptive Tutor and its Applications on Intelligent Textbooks</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Ioannis Anastasopoulos</string-name>
          <email>ioannisa@berkeley.edu</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>UC Berkeley</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Berkeley</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>California</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>United States of America</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Intelligent Tutoring Systems</institution>
          ,
          <addr-line>Crowdsourcing, Intelligent Textbooks, Creative Commons</addr-line>
        </aff>
      </contrib-group>
      <abstract>
        <p>The content ecosystem is an often overlooked component of adaptive tutors and intelligent tutoring systems. A robust and scalable content environment and creation process is critical in sustaining the long-term usage and subject area expansion of a tutor. Open Adaptive Tutor (OATutor), a recently introduced open-source adaptive tutor, produced three textbooks worth of creative commons content with custom built hints and scaffolds and problems sourced from OpenStax. In this paper, we examine how OATutor facilitated the creation of its content over a three-year period, as well as explore its content ecosystem, including the creation process and content team structure. We argue that the created content falls into the realm of intelligent textbooks and can be incorporated into digital textbooks to make them interactive.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>Learnersourcing</p>
    </sec>
    <sec id="sec-2">
      <title>1. Introduction</title>
      <p>
        Intelligent Tutoring Systems (ITS) have consistently been shown to produce significant learning
gains over the past thirty years serving as an indelible paradigm for computer supported instruction
based on mastery learning [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]. Any adaptive system cannot succeed in achieving such goals without a
robust content environment. The content ecosystem of a tutor plays a critical role in facilitating its usage
and adoption, with a substantial portion of early ITS research spent on successfully lowering time and
costs necessary to author content [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ].
      </p>
      <p>
        Until recently, there has been no tutor based on ITS principles that has made its content openly
available via a creative commons or other permissive license. A new open-source tutoring system,
OATutor [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ], has created three algebra texts worth of material, adapted from OpenStax textbooks, and
made it available under a creative commons BY license. To accomplish this, OATutor established a
content environment inspired by the rapidly developing ideas of learnersourcing, allowing for replicable
content creation and curation cycles in addition to its creative commons licensed content [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ].
      </p>
      <p>In this paper, we will discuss how the content environment and ecosystem of OATutor compares
to proceeding tutors, how implementations of learnersourcing-inspired practices helped the OATutor
project facilitate a replicable and scalable content library and content creation routine, and applications
of such an ecosystem in the realm of intelligent textbooks.</p>
    </sec>
    <sec id="sec-3">
      <title>2. Related Work 2.1. Content Creation Environments</title>
      <p>
        For the purpose of enabling users to create content, adaptive tutors and ITS have historically featured
their own unique content creation environments. The earliest content authoring tools for ITS required
200-300 hours of development for the production of a single instructional hour’s worth of content [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ].
      </p>
      <p>
        2023 Copyright for this paper by its authors.
Such time requirements were quickly reduced, as Carnegie Learning developed the Cognitive Tutor
Authoring Tools (CTAT) allowing the development time to drop to 50-100 hours for an instructional
hour’s worth of content [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]. CTAT provided a graphical user interface (GUI) that allowed for creation
of user content with minimal knowledge of coding and programming skills. Content creation could take
place directly on the interface without needing interference or assistance from external sources,
allowing for many independent content creation processes [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ].
      </p>
      <p>
        With the success of CTAT, many emerging adaptive tutors facilitated their content creation through
a set of builder tools focused around providing content creators with an effective GUI. A prime example
of such tutors is ASSISTments, and the ASSISTments Builder functionality. ASSISTments is an
adaptive tutor designed with the instructor as the focus [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]. Reflecting that design philosophy, the
ASSISTments Builder was created with the intent to simplify content creation for instructors [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]. The
builder provides content creators with a GUI designed for easy implementation of student help in the
form of hints and scaffolding, in addition to skill mapping of knowledge components. Additionally, it
successfully matches the lower end of CTAT’s estimate of 50 hours of development for an instructional
hour’s worth of content while also eliminating any requirement for external programming knowledge
[
        <xref ref-type="bibr" rid="ref7">7</xref>
        ]. The ASSISTments Builder also introduced support for variabilization directly into its GUI content
builder, thus helping facilitate additional potential for a content creator to easily generalize their
problems [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]. Overall, these features became standard in many future GUI problem builders, and
established a baseline for what features a content builder tool should be able to support.
      </p>
      <p>
        While GUI builders have increased in popularity due to the aforementioned innovations, there are
various challenges still present in their development. It can be difficult for instructors to constantly have
to learn new interfaces for software to incorporate into their curricula [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ]. New systems are rapidly
developed and introduced to the educational environment, and with content builders and interfaces
being unique, it can be challenging to onboard individuals and have them dedicate the necessary time
to familiarize themselves with the builder. Once instructors get past the learning curve, however, they
can then efficiently incorporate systems into their curriculum [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ].
      </p>
      <p>
        An additional challenge that arises with the innovations of content builders lies in the complexity of
problem creation. With the focus of the progression of content builders lying in decreasing building
time, the ability to design more complex problems with additional capabilities is sometimes lost in the
process [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ]. The question then arises as to how to strike a balance between providing creators with
enough freedom to develop the problems they want, while also optimizing builders for time efficiency
and with an approachable learning curve.
2.2.
      </p>
    </sec>
    <sec id="sec-4">
      <title>Adaptive Content at Scale</title>
      <p>
        Differentiated instruction, or an individualized prescription of practice is an essential component of
modern tutoring systems, producing higher learning gains in experiments in comparison to non-adaptive
variants [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ]. A main advantage lies in individualizing the tutoring experience, as this type of content
can provide students with more appropriate problems conditioned on their skill mastery [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ]. Many
ITS, such as Cognitive Tutor (now MATHia), have been widely deployed in classrooms where they
continue to show significant learning gains over business-as-usual instruction [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ]. Tutoring systems,
like ASSISTments, are also common grounds for launching content-based learning experiments [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ].
These systems could be seen as a type of interactive, adaptive textbook, whereby the student only
interacts with content that has not yet been mastered.
      </p>
      <p>
        Khan Academy hosts one of the largest collections of content for various subjects, distributing
video content at scale [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ], and could be considered one large, grade-spanning, course. With increased
usage due to the recent rise of online learning, Khan Academy as a platform demonstrates the
importance of tutoring content existing at such a large scale and that being able to support learners at
their own individual pace can be critical for their popularity [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ]. Khan Academy secured large amounts
of support during its early years, including a two-million-dollar grant [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ] and still resorted to AI
language learning models to draft some of its content to meet supply demands [31]. Unlike Khan
Academy, ALEKS is an ITS, and provides adaptive content through its online service [15]. Grounded
in Knowledge Space Theory, ALEKS was developed to provide students with an online tutor focused
on personalized content. With proven learning gains comparable to those of classroom instruction,
ALEKS distributes hundreds of lessons and content for the K-12 environment [16]. However, in order
to sustain such a repository and a service, ALEKS is presented as a premium service [15]. There is a
required fee to use the entire collection of ALEKS’s content and services, providing yet another instance
with a visible financial barrier preventing affordable and simply replicability for a successfully scaled
content environment.
      </p>
      <p>
        Teachers have been successfully crowdsourced to produce content within tutoring systems. The
aforementioned system of ASSISTments allows content created for its system to be accessible to
anyone through its community features [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]. ASSISTments then uses resources such as student
comments to help maintain content, and make minor mistakes, such as spelling errors, available to the
content authors [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]. Additional challenges that arise from such a strategy lie in both overcrowding the
system with content that is not widely used, as well as lacking a preventative measure to stop incomplete
or incorrect content from making it onto the platform in the first place. While revising content after it
has been published, and providing a platform for users to give feedback to content creators is important,
incorporating content into a curriculum can be difficult for an instructor if there are large amounts of
unedited and unsupervised problems, an issue that is reflected amongst many community-focused
digital platforms such as Open Educational Resources [17].
2.3.
      </p>
    </sec>
    <sec id="sec-5">
      <title>Crowdsourcing and Learnersourcing</title>
      <p>The most basic definition of “crowdsourcing” revolves around a “proposer” reaching out to groups
of individuals for participation in a “voluntary undertaking of a task”, usually in an online environment
[18]. Crowdsourcing involves a direct benefit for said individuals, usually in the form of financial
compensation, in order to incentivize involvement. Crowdsourcing itself features a set of challenges, as
providing an appealing incentive over a large duration of time can be difficult when paired with the
effort required to identify and recruit potential participants [19]. However, once these challenges are
overcome, it is possible to create a beneficial environment, utilizing the skillset of said participants. To
achieve this desired outcome at scale, potential crowdsourcers need to ensure their provided incentive
is motivating enough for participants to maintain a long-term involvement within the project, while also
making sure to allocate resources and participants in a “flexible manner” [19].</p>
      <p>In regard to providing content to educators, Open Educational Resources (OERs) are a key
exemplifier of crowdsourcing in education. OERs serve as collections of different types of educational
information (from worksheets, to lesson plans, to videos), under either an open license, or in public
domain [20]. The crowdsourcing model varies from resource to resource, but there is a united idea of
individuals being able to contribute and use content freely. Some OERs feature crowdsourcing
incentives for financial sustainability of the platform (referred to as a Donations Model) while others
rely on external sponsors to support the openness of the content (referred to as a Sponsorship Model)
[21]. While there are additional financial models for different OERs, a main challenge remains that
some form of funding needs to exist to keep the resource and the ability to re-distribute content
functioning, even if the content itself is free, and the users don’t directly contribute to the financial
model. Additionally, OERs face the challenge of maintaining high-quality content [17]. With anyone
being able to submit their creations in most OER services, high levels of moderation and tools allowing
the communities to provide feedback and concerns are necessary to navigate these types of
crowdsourced content ecosystems.</p>
      <p>With the challenge of a financial barrier persisting in the crowdsourcing ecosystem, as well as the
necessity for content to be created by qualified individuals, a subclass of crowdsourcing known as
learnersourcing arises. Within learnersourcing, the potential participant is now someone who is
particularly knowledgeable of the field, usually taking the form of a recent (or current) learner [22].
The incentive transforms from something usually financial into a form of learning, or reinforcement of
a subject, for the participant learner. With the learnersourced task revolving around content the learner
is familiar with, involvement in the task allows the display of expertise and creativity on the participants
end. This stands to benefit the participant learner through the “Generation Effect”, the fact that students
recall information better if they have generated it themselves [23]. Thus, learnersourcing stands as a
relationship that helps provide expert content without any financial difficulties, while also directly
helping learners master a subject.</p>
      <p>Learnersourcing serves as a relatively new idea in the crowdsourcing community, so few systems
have had the chance to incorporate it. The system PeerWise allows student creation and sharing of
“formative practice questions” directly through the system, allowing for instructors to provide student
drive supplement to the course material [24]. RiPPLE serves as an adaptive learning platform that
incorporates an aspect of learnersourcing, partnering with students to create resources for the system.
Within RiPPLE, students can create various questions either by themselves, or in a group, with the
ability to also review and customize content from other students [24]. With learnersourcing on the rise,
and systems such as RiPPLE being able to incorporate it partially but effectively, the framework appears
to be able to create a beneficial ecosystem between learners and content availability at scale.
2.4.</p>
    </sec>
    <sec id="sec-6">
      <title>Intelligent Textbooks</title>
      <p>Outside of classic tutoring systems, attempts to scale content can also be found within intelligent
textbooks. Through the assistance of AI as well as frameworks such as Knowledge Space Theory, there
has been a push for the creation of adaptive digital textbooks [27]. Textbooks already offer large
amounts of accessible and scaled content, so an alternative approach to scaling an adaptive
contentbase can be to facilitate adaptivity within an already scaled content medium. Utilizing approaches
developed for ITS, web-based textbooks have explored the usage of adaptive content presentation and
content recommendation [28]. However, many difficulties still remain as to mapping between textbook
content and “complex” activities [32].</p>
      <p>Machine learning models, such as FACE, have been developed to advance keyphrase extraction and
support student modeling, with end goals of creating learning platforms that combine adaptive
textbooks with interactive content [28]. This type of student modeling allows implementations of and
connections to external content, allowing for the merging of supplementary material onto an intelligent
textbook [29]. Paired with early attempts to generate questions based on textbook learning objectives
[30], we argue that intelligent textbooks position themselves as a comparable tool to adaptive tutors.
Beyond logging, intelligent textbooks facilitate interactivity, instead of a static story about science
inquiry, thus allowing for various forms of student personalization. With additional room for research
on incorporation of learning-objective focused content into intelligent textbooks [30], they serve as a
rigid foundation for scaled content.</p>
    </sec>
    <sec id="sec-7">
      <title>3. The OATutor Content Ecosystem</title>
    </sec>
    <sec id="sec-8">
      <title>3.1. Introduction to OATutor</title>
      <p>
        Development on OATutor began in late 2019, with the system’s open sourcing taking place in April
of 2023. OATutor was built upon the foundation of the eight ITS principles, being supported by years’
worth of literature showcasing the display and effectiveness of ITS-like systems [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ]. OATutor features
knowledge tracing-based mastery learning assessment, LTI support for educational systems such as
Canvas, and A/B testing capabilities to empower rapid experimentation in the learning sciences.
      </p>
      <p>
        OATutor was pilot tested in college algebra classrooms in a community college for a total of nine
course offerings over the period of five semesters, in which feedback from the course instructor was
used to iterate and improve upon the system, resulting in additions to the system’s feature list. The
open-source release of the tutor includes comprehensive adaptive content for three different levels of
algebra, with lessons curated from OpenStax’s algebra textbooks [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. Furthermore, OATutor has
displayed noticeable learning gains in early research on the system, when comparing hints generated
by the OATutor team to those degenerated by ChatGPT [25].
3.2.
      </p>
    </sec>
    <sec id="sec-9">
      <title>Building Content in OATutor</title>
      <p>Content creation and curation for OATutor does not require the use of a “builder interface” as present
in previously discussed systems. To address the difficulties of instructors having to adapt to new
interfaces to utilize tutors in their classroom, as well as to support efficient research capabilities with
content, OATutor uses spreadsheets as its basis for building content (Figure 1). Either through Google
Spreadsheets or through Microsoft Excel, individuals create their content on a likely-familiar interface.
Even if an individual is unfamiliar with the spreadsheet interface, there are large collections of resources
widely available as to how to use them, with the OATutor team also offering OATutor-specific user
resources.</p>
      <p>When examining the spreadsheet format, the different sections of a content item are split into
columns and rows. The goal of formatting the spreadsheet in this manner was to facilitate a content
creation environment designed for creating problems with help features, while also supporting content
curation from OERs and textbooks. Thus, the structure found within the spreadsheet attempts to emulate
the basic component of a textbook question, while providing additional fields to support the help
interface of OATutor. The “Problem Name” column denotes an annotated version of the section title,
in an effort to group relevant problems together. The “Row Type” column defines the information each
row is providing, separated into “problem, step, hint, scaffold.” The spreadsheet interface allows for
each hint to have its own dedicated row, allowing for effective implementation of help systems.</p>
      <p>The “Title” and “Body Text” columns can be used for any row type. For problems and steps, they
reflect the title of the problem, and an explanation, while for hints and scaffolds they dictate the text
that appears in the hint interface. The “Answer” and “answerType” columns are used specifically for
row types that require user input (steps and scaffolds). “Answer” serves as the correct answer to a given
question, and “answerType” indicates how the system treats the answer: “string” answers have to be
written exactly by the student, “algebra” answers allow any simplification, and “mc” answers allow for
multiple choice. “HintID” and “Dependency” define the ordering of different hints and scaffolds, as
well as what prior hints are required to view subsequent ones. “mcChoices” is exclusively used for
multiple choice problems and hosts the set of possible solutions. One of the present choices must match
the “answer” entry in order to properly work (an automated script checks for such issues during the
editing process).</p>
      <p>Images can be integrated into the problem through the “Images” column by using a direct image
url. Allowing for individual hints and scaffolds to be treated as rows further supports this integration,
as the placement of an image can be clearly defined within a problem based on the row it is placed in.
The “Variabilization” column allows for the possible inputs of different variables, and variabilization
can be applied to everything from body text to mcChoices. The “parent” column (not pictured) is used
exclusively for sub-hints and sub-scaffolds and indicates to which previous scaffold such rows belong.
Finally, there are three sourcing related columns (also not pictured). “OER src” indicates the respective
source of a problem for proper attribution. “KC” refers to the knowledge component as defined in the
original source, and “taxonomy” refers to the type of taxonomy the original source utilizes (common
core standards, custom format, etc.).</p>
      <p>An automated script converts the problems created on the spreadsheet into problems in the system’s
frontend. At the same time, the script automatically checks if the problem is properly formatted, and
provides feedback automatically in the process, emphasizing potential errors in the problem structure.
In order to support additional research use cases, the script can be run at a local level as well.</p>
      <p>While the spreadsheet interface is simplistic to be approachable, it does not face the aforementioned
limitations of design restrictions. With OATutor being opensource, anyone is able to build upon the
capabilities of the interface and create structure for any problem type that may be required for their
individual research or classroom needs. Thus, it is possible to maintain a user-friendly basic interface,
while allowing for complex design if necessitated in specific usage cases of the tutor.
3.3.</p>
    </sec>
    <sec id="sec-10">
      <title>Content Community</title>
      <p>
        Inspired by the benefits of learnersourcing, the OATutor content team is crowdsourced with a
method that resembles the foundations of learnersourcing. Content team members are not recent
learners but instead experienced learners with tutoring experience on their respective subject. Because
of this, “learning” cannot be the provided incentive for their participation. Instead, content team
members are recruited through research apprenticeship programs (such as UC Berkeley’s URAP) with
the motivation to work in a UC Berkeley research environment, as well as contribute to the open-source
nature of the project [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. As a benefit to the tutor, however, this additional requirement also helps
eliminate the risk of low-quality content, as the content building community is comprised of a
demographic deeply familiar with the material.
      </p>
      <p>To maintain the content community pipeline, the OATutor content team holds bi-weekly meetings
to facilitate discussion on potential difficulties that may arise during content creation and curation.
Individual content creators contribute their thoughts and questions to the meeting, with their feedback
being used to iterate upon the system and interface design further. These meetings further allow to
ensure the fostering of motivation and connection within the team, helping to facilitate a successful
crowdsourced environment.</p>
      <p>The recruited individuals are split into content creators and editors. Editors are more experienced
creators who have been with the team for longer than a semester and are deeply familiar with the content
structure of OATutor. Editors review content created by the rest of the team, and make any necessary
changes before the content is pushed to the frontend of the system. Furthermore, they provide feedback
to content creators, helping facilitate an efficient content pipeline with a rigorous editing and review
process. This further protects the quality of the content, while also helping new creators adjust to the
system without having to master content creation alone.</p>
      <p>Originally, content creators worked on individual spreadsheets, which were then curated into a single
editor spreadsheet for review. After editor review, the content was then pushed to a “master document”
spreadsheet which was converted to the material on the system’s frontend. However, this pipeline was
shifted to have content creators work directly on the editor sheet. With an updated automatic script,
editors and content creators alike were able to preview what their problems would appear like on the
system, allowing for swifter handling of bugs and formatting issues, as well as more immediate
feedback on the side of editors.
3.4.</p>
    </sec>
    <sec id="sec-11">
      <title>Approach to Content Curation</title>
      <p>For the creation of high-quality content within the system, and ensuring the content is usable within
classrooms, a study of various OERs was conducted to determine an appropriate resource to curate
content problems from (with the content team creating hints and scaffolding for said problems). After
examining over 25 potential resources for content curation (Figure 2), five main potential candidates
were selected (colored in green), with three additional backup resources (colored in yellow). Upon
further inspection of the top five resources, OpenStax was selected as the main resource to curate
content from.</p>
      <p>OpenStax textbooks were used as the foundation for the first three collections of algebra lessons in
OATutor. Each collection is classified as a “book” and includes problems for every lesson from the
respective OpenStax textbook. Each lesson contains 15-30 problems depending on OpenStax
availability, each with custom-generated hints and scaffolds from the content team. Individual problems
are tagged with appropriate knowledge components reliant on categorization found within the OpenStax
textbooks. This allows for a direct mapping between every individual OATutor problem, and an
OpenStax question. Such mapping can also occur at the lesson level, as problems are separated into
OATutor lessons based on the respective OpenStax chapter.</p>
      <p>This one-to-one mapping with the OpenStax curriculum has found great utilization in pilot tests of
the system, where OATutor lessons served as supplemental material in a community college classroom
to accompany the respective OpenStax textbook material of the curriculum. Additionally, due to the
precise tagging of the content and the ability for instructors to assign lessons independently, the content
can be incorporated into any respective algebra curriculum, even if said curriculum does not replicate
the OpenStax chapter order. With the open-source nature of the content, further potential exists for the
content itself to be modified appropriately for any curriculum needs, without the requirement of
building new content from the ground up.</p>
    </sec>
    <sec id="sec-12">
      <title>4. Applications in Intelligent Textbooks</title>
    </sec>
    <sec id="sec-13">
      <title>4.1. Textbook Integration</title>
      <p>As discussed regarding its usage with OpenStax textbooks, there is a visible benefit in using an
adaptive lesson to supplement a digital textbook. With recent efforts to generate content from digital
textbooks showing successful results [26], OATutor can create a bridge between digital textbooks and
adaptive content generated from them. The content ecosystem presented above replicated the
learningobjective focused content that recent efforts have attempted to create for intelligent textbooks [30], but
instead of utilizing machine learning or AI algorithms, the content creation was facilitated by a
crowdsourced team of learners.</p>
      <p>
        With a present need for interactive and adaptive content in the field of intelligent textbooks, the
OATutor content ecosystem accomplishes curation of three textbooks worth of algebra content with
unique hints and scaffolds for the accompaniment of each problem. This demonstrates feasibility of
learning-objective focused content generation directly from digital textbooks and creates the
opportunity to replicate the content ecosystem for any other necessary textbooks. The created content
can be easily integrated and incorporated within textbooks, or classroom curricula centered around
them, as exemplified in OATutor’s pilot tests [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. Thus, we argue that creating such an ecosystem and
a pipeline for content generation from textbooks is within the spirit of intelligent textbooks.
      </p>
      <p>Within OpenStax specifically, a future incorporation of OATutor can be imagined. It would be
reasonable to embed OATutor lessons within the individual OpenStax textbook pages. As OpenStax
chapters are structured with theory followed up by problems, and said problems are what has been
curated into OATutor, it would be reasonable to feature a section prompting learners to practice the
content they have just been exposed to directly within the textbook page. This application and
incorporation of OATutor would require minimal work, as the lessons have already been curated.</p>
      <p>An alternative method of OATutor embedding could be facilitated by having individual problems
within the textbook directly linked to the corresponding tutor questions (or the tutor question completely
replacing them). OATutor would track learner mastery throughout the lesson, and would gray out, or
disable, subsequent questions of skills that have already been mastered. To avoid concerns about
altering the nature of a textbook, for example if the ability to print a physical copy is still desired,
OATutor’s interactive elements could be enabled in a subtle way that does not change the look of the
printed textbook.</p>
      <p>Beyond OpenStax, the discussed approaches can be generalized to other digital textbooks. The
OATutor approach to crowdsourced content production by transcribing OER content and augmenting
it with scaffolding and hints proved sustainable over three years. Such a framework can be applied to
other textbooks, and with the open sourcing of OATutor’s mastery algorithms, allow for regular digital
textbooks to provide adaptive content.
4.2.</p>
    </sec>
    <sec id="sec-14">
      <title>Other Implementations</title>
      <p>Additional pilots of the system could also provide beneficial information about the usability of such
content. While supplemental content involves students interacting with the system’s lessons, direct
integration into curriculums in the form of homework or assessments can provide additional insights
into advantages and disadvantages of the current content structure. Facilitation of such usage could also
encourage modification of the system’s content to more directly reflect assessment requirements of a
classroom, allowing for further information collection and research opportunities to examine these
necessities and connections to intelligent textbooks.</p>
      <p>In terms of future improvements, the curation from OpenStax (and any other future digital textbook)
could be iterated upon to automatize the problem curation and require direct intervention from the
content team for hint and scaffold creation (serving as the current original work on the team).
Furthermore, if the current trends of ChatGPT experimentation for hint generation continue, and the
learning gains of ChatGPT help approach those of manual hints and scaffolds, the entire content creation
process could be greatly accelerated, and easily integrated with digital textbooks, requiring only editor
revision. Such work would require a reformation of the described content ecosystem, and additional
studies to equate the learning gains.</p>
    </sec>
    <sec id="sec-15">
      <title>5. Discussion and Conclusions</title>
      <p>With the entirety of OATutor open-sourced, in addition to a crowdsourced community of learners,
the novelty of the content ecosystem should be replicable. Further research is required to determine the
time period necessary to fully replicate such an ecosystem, in addition to examining possible
modifications and expansions. This includes other organizations and laboratories attempting to replicate
the learner-focused crowdsourcing ecosystem of OATutor for their own content creation in addition to
creating content at OATutor’s scale and efficiency.</p>
      <p>Replicability and scaling of the content ecosystem has room to be explored. OATutor successfully
created its content community due to systems like UC Berkeley’s Undergraduate Research
Apprenticeship Program (URAP). Although national programs like the National Science Foundation's
Research Experiences for Undergraduates (REU) are still available, relying on such a program to
support long-term content ecosystems can be difficult. Even with long term facilitation, there are
additional crowdsourcing challenges that still persist, such as cohesiveness. Specifically, the individual
voice of each learner is reflected in the problem they help create. Each learner will structure hints and
scaffolds in a slightly unique manner, sometimes resulting in a mesh of different or even conflicting
methodologies within the same lesson. While OATutor suppressed this issue by assigning one lesson
per individual creator, this solution only works at such a granular level, and cannot be replicated for an
entire book.</p>
      <p>The open sourcing of an adaptive tutoring system with a crowdsourced community of learners and
an open content pipeline opens pathways for replicable and novel research to accelerate in the learning
sciences. With low-entry-level content building capabilities, but the potential to build upon the system
to design content of any complexity, OATutor challenges the current standard for content creation in
research environments, while also supporting effective classroom integration through its features.
Furthermore, as digital textbooks advance in ways that foster inclusion of active content, OATutor’s
structure enables opportunities to study and design curricula utilizing the combined capabilities of
textbooks and tutors and creates new potential for research on digital textbook integration.</p>
    </sec>
    <sec id="sec-16">
      <title>6. Acknowledgements</title>
      <p>This paper was peer-reviewed by Zachary Pardos, UC Berkeley, USA. This Word template was
created by Aleksandr Ometov, TAU, Finland. The template is made available under a Creative
Commons License Attribution-ShareAlike 4.0 International (CC BY-SA 4.0).</p>
    </sec>
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