Chrysafiadi Konstantina

Dr. Chrysafiadi Konstantina

Informatics, University of Piraeus, Piraeus, Attikí, Greece
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Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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11 March 2014 in IEEE Transactions on Fuzzy Systems
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Chrysafiadi KonstantinaChrysafiadi Konstantina
Chrysafiadi Konstantina
MVMaria Virvou
Maria Virvou
In this paper, a novel approach to web-based education that performs individualized instruction on the domain of programming languages is presented. This approach is fully implemented and evaluated in an educational application module, called fuzzy knowledge state definer (FuzKSD). In particular, FuzKSD performs user modeling by dynamically identifying and updating a student's knowledge level of all the concepts of the domain knowledge. The operation of FuzKSD is based on fuzzy cognitive maps (FCMs) that are used to represent the dependences among the domain concepts. FuzKSD uses fuzzy sets to represent a student's knowledge level as a subset of the domain knowledge. Thus, it combines fuzzy theory with the overlay model. Moreover, it employs a novel inference mechanism that dynamically updates user stereotypes using fuzzy sets. It should be noted that the overlay model and stereotypes constitute two widely used methods for user modeling. However, they have not been combined with fuzzy sets thus far in the literature. The gain from this novel combination is significant as a student level of knowledge is represented in a more realistic way by automatically modeling the learning or forgetting process of a student with respect to the FCMs and thus the system can provide individualized adaptive advice. The application of this approach is not limited to adaptive instruction. It can also be used in other systems with changeable user states, such as e-shops, where consumers' preferences change over time and affect one another. Therefore, the particular module constitutes a novel generic fuzzy tool, which offers dynamic adaptation to users' needs and preferences of adaptive systems.

17 November 2022 in Education and Information Technologies
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Chrysafiadi KonstantinaChrysafiadi Konstantina
Chrysafiadi Konstantina
MVMaria Virvou
Maria Virvou
George A TsihrintzisGeorge A Tsihrintzis
George A Tsihrintzis
Ioannis HatzilygeroudisIoannis Hatzilygeroudis
Ioannis Hatzilygeroudis
Nowadays, the improvement of digital learning with Artificial Intelligence has attracted a lot of research, as it provides solutions for individualized education styles which are independent of place and time. This is particularly the case for computer science, as a tutoring domain, which is rapidly growing and changing and as such, learners need frequent update courses. In this paper, we present a thorough evaluation of a fuzzy-based intelligent tutoring system (ITS), that teaches computer programming. The evaluation concerns multiple aspects of the ITS. The evaluation criteria are: (i) context, (ii) effectiveness, (iii) efficiency, (iv) accuracy, (v) usability and satisfaction, and (vi) engagement and motivation. In the evaluation process students of an undergraduate program in Informatics of the University of Piraeus in Greece participated. The evaluation method that was used included questionnaires, analysis of log files and experiments. Also, t-tests were conducted to certify the validity of the evaluation results. Indeed, the evaluation results are very positive and show that the incorporated fuzzy mechanism to the presented ITS enhances the system with Artificial Intelligence and through this, it increases the learners’ satisfaction and new knowledge learning and mastering, improves the recommendation accuracy of the system, the efficacy of interactions, and contributes positively to the learners’ engagement in the learning process.

1 June 2022 in Knowledge-Based Systems
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Chrysafiadi KonstantinaChrysafiadi Konstantina
Chrysafiadi Konstantina
SPSpyros Papadimitriou
Spyros Papadimitriou
MVMaria Virvou
Maria Virvou

29 July 2019 in Multimedia Tools and Applications
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SPSpyros Papadimitriou
Spyros Papadimitriou
Chrysafiadi KonstantinaChrysafiadi Konstantina
Chrysafiadi Konstantina
MVMaria Virvou
Maria Virvou

16 August 2023 in International Journal on Artificial Intelligence Tools
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Chrysafiadi KonstantinaChrysafiadi Konstantina
Chrysafiadi Konstantina
MVMaria Virvou
Maria Virvou
GTGeorge A. Tsihrintzis
George A. Tsihrintzis
IHIoannis Hatzilygeroudis
Ioannis Hatzilygeroudis

16 February 2023 in Multimedia Tools and Applications
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Chrysafiadi KonstantinaChrysafiadi Konstantina
Chrysafiadi Konstantina
MKMargaritis Kamitsios
Margaritis Kamitsios
MVMaria Virvou
Maria Virvou
An educational game aims to employ the pleasant and fascinating environment of a game for educational purpose. However, when the game’s educational content or playing environment does not match with the player’s learning needs or game-playing skills, the player can find the game either too easy or too difficult and decide to drop it. Therefore, a successful educational game has to offer Dynamic Difficulty Adjustment (DDA) of both the game’s educational content and the game’s playing environment. Considering the above, in this paper a fuzzy-based DDA mechanism of a 3D-game, that teaches the programming language ‘HTML’, is presented. The game adapts dynamically the difficulty of battles and mazes navigation to each individual player’s skills. The novelty of the presented game lies on the application of DDA in the two dimensions (educational content and playing environment) of an educational game and on the use of fuzzy logic for succeeding balance between the game’s difficulty and the user’s playing skills. The adaptation is realized in real-time, during the playing and not each time the player changes game level/track. Furthermore, fuzzy logic allows to apply DDA without the need of many learning data, like other Artificial Intelligence techniques for DDA (i.e. machine learning techniques). The presented game was evaluated through a comparative evaluation, which included questionnaires, an experiment in real conditions and t-test statistical analysis method. The evaluation results showed that the incorporated adaptation mechanism increases the user’s motivation and succeeds to keep players’ interest for the game undiminished.