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<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta>
      <journal-title-group>
        <journal-title>Y. Artamonov);</journal-title>
      </journal-title-group>
    </journal-meta>
    <article-meta>
      <title-group>
        <article-title>Adaptive user interfaces based on behavioral analysis</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Yevhen Artamonov</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Tetyana Okhrimenko</string-name>
          <email>t.okhrimenko@npp.nau.edu.ua</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Iurii Golovach</string-name>
          <email>iurii.golovach@gmail.com</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Daniil Krant</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Andrij Radchenko</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Kostiantyn Radchenko</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Taras Zaloznyi</string-name>
          <email>taras.zaloznyi@gmail.com</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>National Aviation University</institution>
          ,
          <addr-line>Liubomyra Huzara Ave. 1, Kyiv, 03058</addr-line>
          ,
          <country country="UA">Ukraine</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>State Scientific and Research Institute of Cybersecurity Technologies and Information Protection</institution>
          ,
          <addr-line>Maksym Zalizniak Str., 3/6, Kyiv, 03142</addr-line>
          ,
          <country country="UA">Ukraine</country>
        </aff>
      </contrib-group>
      <volume>000</volume>
      <fpage>0</fpage>
      <lpage>0001</lpage>
      <abstract>
        <p>The article reveals the possibilities of developing and applying adaptive interfaces that involve analyzing user behavior in e-learning systems. Methods of content adaptation based on personalization are a relevant direction in e-learning systems, because they allow taking into account the needs and requirements of users in an automatic mode. A user model is presented, which includes a comprehensive approach to representing both objective (progress indicators, performance, etc.) and subjective parameters (likes, user feedback, etc.), which allows personalizing the material and interface in accordance with individual requests and capabilities of users. The Levenshtein method determines the similarity between user behavior vectors and predefined learning templates, which allows the system to dynamically adjust data presentation scenarios to support the optimal learning trajectory. This method was used in the MS SQL Server online learning system and in a hardware-software complex for learning Braille. Changing the scenarios for displaying materials in accordance with a specific user category demonstrated significant improvements in learning success rates. Experiments showed that automatic switching of scenarios allowed the system to adapt to the level of learning material mastery by the user, which increased motivation and productivity. Each scenario of displaying educational materials provided for different levels of task complexity and depth of presentation of educational material, so changing scenarios during training added interactivity and increased the level of friendliness of the learning environment, which adapted to the pace and style of each user. System load assessment showed that the Levenstein method with minimal use of hardware resources solved the problem of measuring the similarity between user behavior and learning templates, which allows the system to adapt content in real time, taking into account the current productivity, interest and progress of the user. Minimization of requirements for system parameters allowed using this method in a hardwaresoftware complex for teaching Braille to the visually impaired. The article separately highlights the tasks and requirements for implementing such systems: the complexity of development, requirements for algorithm performance, ensuring user data security, and constant updating of user models. Solving these problems is crucial for fully realizing the potential of dynamic content visualization in e-learning systems. The constant development and improvement of adaptive technologies have an impact on the future of education because technologies continue to develop, user requests are becoming more diverse, and the use of personalization is introduced into all spheres of life and education is no exception.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;adaptive interface</kwd>
        <kwd>behavioral analysis</kwd>
        <kwd>learning systems</kwd>
        <kwd>medical diagnostic systems 1</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        Adaptive user interfaces have long become a widespread phenomenon, which is used in almost all
software and some hardware-software systems. Developers compete in methods and means of
dynamically adjusting parameters for each user, recommendation systems have turned into
templates and libraries that are used in the development of new software complexes, and affect the
formation of content, a list of menu items, and product offers in accordance with individual user
preferences, thus ensuring intuitive interaction with software systems [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. In modern systems with
adaptive functionality, the ability to analyze and respond to changes in user behavior has become a
central issue that affects the formation of interface design, content, and available functionality [
        <xref ref-type="bibr" rid="ref2 ref3">2, 3</xref>
        ].
      </p>
      <p>The main goal of the study is to implement a new method for determining user categories based
on behavior analysis in adaptive e-learning systems. The method involves using the Levenshtein
distance, which determines the similarity of rows, to assign a user to a certain category based on the
analysis of the trajectory of passing through educational content. The implementation of this method
in already operating systems with a constant flow of users will allow us to determine the feasibility
of using this approach and the effect of its implementation. The experiment involves the use of two
systems with different ideologies of building the structure of the program code and different
deployment formats, so the use of a common method for determining the user category will better
reveal its advantages and disadvantages.</p>
      <p>The experiments will show whether the automatic switching of content display scenarios remains
unnoticed by users by assessing the number of users' cancellations of automatic system decisions
(the presence of such a fact will indicate confirmation of the correctness of the chosen approach to
assessing user behavior, which correctly and expectedly affected the display of educational content).
Successful verification of the operation of the Levenshtein method on real data and in real systems
will allow us to reveal the potential of this method for use in adaptive information systems that base
decision-making on user behavior.</p>
      <p>The behavior of a computer system when used by a large number of people is one of the critical
factors influencing the choice of a system on the software market, therefore, in research in the field
of adaptive interfaces and learning systems, the speed and use of system resources are additional
parameters in the evaluation of the proposed methods. That is why the need to provide each user
with a comfortable working environment is often ignored, as a rule, remaining at the conceptual
level, because the implementation of these methods increases the requirements for system
characteristics.</p>
      <p>The search for methods for adapting systems to the requirements and needs of users still remains
open, and research is being conducted in the areas of providing tools for assessing individual user
characteristics, creating user models, and determining the effectiveness of using systems for the tasks
set. However, the fact that there is a tendency to automate learning processes (preparation of
materials, assessment of the level of knowledge and mastered material, determination of learning
trajectories, etc.) does not reduce the role of participation of teachers, instructors or trainers who use
traditional tools and methods of learning.</p>
      <p>
        Approaches to building systems with elements of adaptability have demonstrated their
applicability in almost all areas of activity. More than 70 articles from various scientific disciplines
describing multi-agent and multi-scenario system approaches were reviewed. Articles [
        <xref ref-type="bibr" rid="ref4 ref5">4, 5</xref>
        ] analyze
the organization of training courses that are adapted to the needs and requests of users. In [6], the
dissemination of public information using adaptation to user requests is separately considered. The
potential of various approaches in decision support systems for healthcare is investigated in articles
[7, 8]. Article [9] presents an assessment of the construction of a multi-agent training system. The
analysis of scientific research confirmed the relevance of using adaptation to user behavior in
software systems and indicated the feasibility of researching new methods for determining the user
category depending on his behavior, because practical application distinguishes the described
approaches, determining their real relevance and effectiveness.
      </p>
    </sec>
    <sec id="sec-2">
      <title>2. Adaptive user interfaces in the e-learning systems</title>
      <p>The use of dynamic interfaces and dynamic content generation in e-learning systems implies a
transformation to modern education [10], because the adaptation of content in real-time to the
behavior and progress of the student opens up opportunities for personalized learning taking into
account the unique needs and preferences of each student. The dynamic nature of interfaces and
content takes user interaction with e-learning systems to a new level and ensures that educational
content will remain relevant and understandable for a longer time, regardless of the student’s basic
level of knowledge [11].</p>
      <p>Adding new parameters of interface dynamics allows for the continuous development of
educational platforms with constant feedback on user actions and reactions [12]. In e-learning
systems, adaptation parameters include content presentation, navigation paths, interactive elements,
the number and complexity of tasks, and the presence of interactive prompts. For example, if a
student constantly faces the problem of finding the last read section of the educational material, then
the interface can be adapted by providing a link to this section or its summary in the list of recently
viewed materials. In another case, the student could not pass a certain category of tests because he
did not have multimedia tools available on the computer, so for him these tests were excluded from
the list of tasks.</p>
      <p>Although each case of interaction with the system is unique, it is possible to combine users into
groups and build standard solutions for adapting the system to the requirements of each group. This
approach solves the problem of the complexity of the software implementation of adapting the
system to the requirements of each individual user and introduces the concept of display scenarios
for user groups.</p>
      <p>A user model is used for combining users into groups, and the combination into groups occurs
based on the coincidence of certain groups of parameters. The user model used in the developed
systems has the following form:
=
,
,
=</p>
      <p>,
=
,
, . . . ,
,
, . . . ,
,
where
where OP is the set of objective parameters, SP is the set of subjective parameters.</p>
      <p>The process of filling the user model should have the following classification features: implicit
accumulation, individuality, dynamism, durability, and descriptiveness [10]. To adapt the system
itself, its model is also introduced, which is divided into two sets of parameters:</p>
      <p>– interface parameters (IP): these parameters cover all elements related to the presentation and
interaction of educational resources. They include layout design, navigation structures, accessibility
functions, and any other aspects that affect the user's direct interaction with educational content;
– functional parameters (FP): these parameters are related to the main functions of the e-learning
system. They include content delivery mechanisms, performance tracking, feedback systems, and
any other operational capabilities that support the learning process.</p>
      <p>Then the e-learning system model can be represented as follows:</p>
      <p>= , ,
=
,
, . . . ,
,
, . . . ,
where IP – the set of interface parameters, FP – the set of functional parameters.</p>
      <p>To implement the method of dynamic visualization of educational content, it is necessary to
evaluate the user parameters and assign the user to a certain group. Then the system can
personalize both the material and the interface according to the individual needs of a given user
group. This approach offers several significant advantages and potential problems. The key feature
of this method is the mechanism of automatic scenario change, which involves dynamic adjustment
of content and learning paths (order of training material and/or test tasks) based on the analysis of
the user’s previous interaction and learning progress.</p>
      <p>It was decided to use the Levenshtein distance to measure the similarity between the user’s
current behavior and predefined learning patterns, determining when to switch scenarios to optimize
the learning process. The Levenshtein distance between two data sets is a measure of the difference
between them, which quantifies the similarity, which in turn helps to decide which group to assign
the user to and which scenario to use [13, 14].</p>
      <p>The Levenshtein distance between two strings is the minimum number of single-character edits
(insertion, deletion, replacement) required to transform one string into another [15]. Formally, it is
defined recursively as follows:
⎧ !"# , , if ! &amp; , = 0,
⎪ − 1, + 1
, = ⎨! &amp; ( , − 1 + 1 , otherwise,</p>
      <p>⎩⎪ − 1, − 1 + , - − 1. ≠ 0- − 1. 1
where , is the Levenshtein distance between the first characters of string and the first
characters of string 0.</p>
      <p>Consider an undirected connected graph with 10 vertices, represented by an adjacency matrix.
The graph has the following structure:</p>
      <p>⬚ 0 1 2 3 4 5 6 7 8 9
⎜⎛ 10 10 01 01 01 10 10 00 00 00 00⎞⎟
⎜ 2 1 0 0 0 0 0 1 0 0 0⎟
⎜ 3 1 0 0 0 0 0 0 1 1 0⎟
⎜ 4 0 1 0 0 0 0 0 0 0 1⎟.
⎜ 5 0 1 0 0 0 0 0 0 0 1⎟
⎜ 6 0 0 1 0 0 0 0 0 0 1⎟
⎜ 7 0 0 0 1 0 0 0 0 0 1⎟</p>
      <p>8 0 0 0 1 0 0 0 0 0 1
⎝ 9 0 0 0 0 1 1 1 1 1 0⎠
We will treat the paths as strings of characters "0149", "0379", "159", "269", "0269", "389".</p>
      <p>Example of Calculation of Levenshtein Distance Between paths 1 and 2 ("0149" and "0379") have
few steps.</p>
      <p>Step 1. Initialization: we start by initializing the dynamic programming matrix with dimensions
&amp; + 1 × ! + 1 , where &amp; is the length of the first string and ! is the length of the second string.
In this case, both strings have a length of 4, so the matrix will be 5 × 5.</p>
      <p>⬚ ⬚ 0 3 7 9
⎛⎜⎜⬚01 012 100 200 300 400⎟⎞⎟</p>
      <p>4 3 0 0 0 0
⎝ 9 4 0 0 0 0⎠</p>
      <p>Step 2. Filling the Matrix: we fill in the matrix D by calculating the minimum cost of edit
operations (insertion, deletion, substitution) required to transform the substring of the first string
into the substring of the second string. We proceed cell by cell:
•
•
•
•
•
•
•</p>
      <p>1,1 compares "0" with "0", which are the same, so the cost is 0.
! &amp; 0,1 + 1, 1,0 + 1, 0,0 + 0 = ! &amp; 2,2,0 = 0.</p>
      <p>1,2 compares "0" with "03", the cost is 1. 1,2 = ! &amp;
1, 0,1 + 1 = ! &amp; 3,1,2 = 1.</p>
      <p>1,3 compares "0" with "037", the cost is 2. 1,3 = ! &amp;
1, 0,2 + 1 = ! &amp; 4,2,3 = 2.</p>
      <p>1,4 compares "0" with "0379", the cost is 3. 1,4 = ! &amp;
1, 0,3 + 1 = ! &amp; 5,3,4 = 3.</p>
      <p>2,1 compares "01" with "0", the cost is 1. 2,1 = ! &amp;
1, 1,1 + 1 = ! &amp; 1,3,2 = 1.</p>
      <p>2,2 compares "01" with "03", the cost is 1. 2,2 = ! &amp;
1, 1,1 + 1 = ! &amp; 2,2,1 = 1.</p>
      <p>2,3 compares "01" with "037", the cost is 2. 2,3 = ! &amp;
1, 1,2 + 1 = ! &amp; 3,2,2 = 2.
0,2 + 1,
0,3 + 1,
1,1 =
1,1 +
1,2 +
0,4 + 1,</p>
      <p>1,3 +
1,1 + 1,</p>
      <p>2,0 +
1,2 + 1,</p>
      <p>2,1 +
1,3 + 1,
2,2 +</p>
      <p>⬚ ⬚ 0 3 7 9
⎛⎜⎜⬚01 012 101 211 322 433⎞⎟⎟</p>
      <p>4 3 2 2 2 3
⎝ 9 4 3 3 3 2⎠
The final cell 4,4 = 2 indicates that the Levenshtein distance between "0149" and "0379" is 2.</p>
      <p>The Levenshtein distance was used in our adaptive learning systems to speed up calculations of
user group membership and measured the similarity between the sequence of user interactions with
the system and predefined patterns of expected behavior. This distance helps determine the need to
change the content display scenario if there is a change in the type of user group membership,
thereby ensuring that the level of complexity of the learning material is appropriate for each student.</p>
    </sec>
    <sec id="sec-3">
      <title>3. Experimental evaluation of automatic scenario switching in adaptive learning systems</title>
      <p>To evaluate the performance of the Levenshtein method in determining the user category, two
systems were used:</p>
      <p>1) the online learning system MS SQL Server, which was used to support the educational process
in courses at a private educational center;</p>
      <p>2) the hardware-software complex for teaching Braille, which was used in children's state
institutions and individually was made in the form of a toy with a sound interface.</p>
      <p>These systems have been used for more than 5 years and the current experiment is a continuation
of the experiment, which is highlighted in the work [16], where the training complexes themselves
are described in more detail. The new method for determining the user category replaced the
previous method, which was based on the number of errors made during testing, and was the number
of participants in the experiment:</p>
      <p>1) 145 participants, when studying MS SQL Server, changed between two scenarios for 13 days
(Table 1 shows the results of scenario changes);</p>
      <p>2) 170 participants, when using the hardware-software complex for studying Braille, changed
between three scenarios during 23 lessons (Table 2 shows the results of scenario changes).</p>
      <p>Number of users with scenario changes at the end of each lesson</p>
      <p>In the MS SQL Server e-learning system, users participated remotely, devoting an average of 3
hours per day to the training course. Braille was not studied every day, but the entire training course
took no more than 2 months, and students were allocated approximately 1 hour per lesson.</p>
      <p>The graphs (Figure 1 and Figure 2) with selected scenarios at the end of the day/lesson show the
trend of scenario changes, which corresponds to the progress of the complexity of the tasks for most
users and the minimum number of reverse scenario switching.</p>
      <p>Number of changed scenarios by working days</p>
      <p>During the experiments, the use of system resources was monitored during the operation of the
new algorithm for determining the user category, which showed a minimal increase in resource
requirements, which allowed the systems to be run on microcomputers (Braille learning).</p>
      <p>Analysis of the obtained data shown:
1) in the e-learning system for studying MS SQL Server, the number of participants in Scenario 1
decreases over time, and in Scenario 2 increases (Figure 3), similarly, in Braille learning there is a
gradual increase to Scenario 3 (Figure 4), which indicates that as the course progresses, more and
160
150
140
130
120
110
100
90
80
70
60
50
40
30
20
10
0
170
160
150
140
130
120
110
100
90
80
70
60
50
40
30
20
10
0
1
2
3
4
5
8
9
10
11
12
13</p>
      <p>Finish
6
Scenario 1
7</p>
      <p>Scenario 2</p>
      <p>Number of users with each scenario at the end of the lesson
more users move from the initial scenario to the next one, which confirms the correctness of the
work of determining the category by the new method;</p>
      <p>2) the decrease in the number of transitions back to scenarios with less complexity also indicates
the correctness of the choice of the user category, which corresponds to the logic of learning and
adaptation to more complex content.</p>
      <p>Selected scenarios by working days
1</p>
      <p>9 10 11 12 13 14 15 16 17 18 19 20 21 22 23</p>
      <p>Scenario 1 Scenario 2 Scenario 3</p>
      <p>The results obtained when testing both systems emphasize the correctness of the choice of the
method for evaluating user categories based on their behavior and the effectiveness of generating
dynamic content in adaptive learning environments, which emphasizes the possibility of
implementing such solutions in adaptive learning systems.</p>
    </sec>
    <sec id="sec-4">
      <title>4. Conclusions</title>
      <p>The practical implementation of the Levenshtein method for determining the user category by his
behavior allowed to control the change of scenarios of displaying educational content in e-learning
systems. This confirmed the correctness of the hypothesis of using the trajectory of the educational
material among a set of objective and subjective parameters in the user model, which allowed to
provision of individual settings of content and interface for each user. The Levenshtein distance with
minimal use of hardware resources solved the problem of measuring the similarity between user
behavior and learning patterns, which allows the system to adapt the content in real time, taking
into account the current performance, interest, and progress of the user. Previous studies [16] have
proven that dynamic adaptation of the display of educational materials improves learning outcomes
by hiding too complex or too simple tasks, which maintains student motivation and contributes to
better educational achievements.</p>
      <p>Experiments have shown that automatic switching of content display scenarios remains
unnoticed by users due to the small number of recalls of automatic decisions.</p>
      <p>Continuous monitoring of user interaction with the system and adjustment of the user model
depending on his behavior allowed to improvement the user's impression of the content, which is
always consistent with the changing needs of the user, his state, or interest. The introduction of the
structure of interface parameters and functional parameters provided a flexible approach to
managing various components of the e-learning system and allowed to integration of the proposed
approach in different forms of teaching and among different groups of users. At the same time, the
implementation of adaptive systems involves the complication of development, the use of complex
algorithms, an increase in the level of protection of user personal data, and constant refinement of
the user model. The degree of use of the potential of dynamic visualization of content in e-learning
systems depends on the solution of these tasks.</p>
      <p>The constant development and improvement of adaptive technologies have an impact on the
future of education because technologies continue to develop, user requests are becoming more
diverse, and the use of personalization is introduced into all spheres of life and education is no
exception.</p>
    </sec>
    <sec id="sec-5">
      <title>Declaration on Generative AI</title>
      <p>The author(s) have not employed any Generative AI tools.
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