Physics-Informed Neural Networks (PINNs) take advantage of physical constraints to improve the predictive performance of neural networks. They have demonstrated remarkable success in physics, chemistry, biology, and medicine, sparking interest in their potential applications in other fields, such as Human-Computer Interaction (HCI). Despite their versatility, PINNs are underutilized in certain disciplines due to the challenge of defining Partial Differential Equations (PDEs) that adequately constrain specific problems. This study investigates the application of PINNs to predict fixations captured by an eye-tracking device, employing equations that model head and eye movements. The data for this study were collected during an experiment involving an adaptive user interface for pilots, encompassing a variety of fixation points and rapid glances. The results establish PINNs as a superior method, achieving a mean absolute error (MAE) of 0.61 for horizontal predictions ( X ) and 0.35 for vertical predictions ( Y ), significantly outperforming the conventional neural network (NN). Additionally, the PINN demonstrated stronger predictive accuracy for vertical gaze dynamics, as evidenced by an R Y 2 of 0.91 compared to 0.85 for the NN. These findings underscore the robustness of the PINN approach in modeling gaze points with enhanced precision and reliability. While conventional neural networks perform adequately, the added benefit of physical constraints in PINNs encourages further exploration of their application in non-natural science domains. These promising results point toward the potential of PINNs in creating more adaptive and context-aware systems for various HCI applications.

This work explores the initial interactions and perceptions of computer engineering students who have no prior experience with low-code platforms. Specifically, undergraduate computer engineering students participated in a comprehensive experiment at the Human-Computer Interaction Laboratory at the University of Patras, adhering to a structured experimental protocol encompassing questionnaire completion, exposure to an introductory video on low-code concepts, eye-tracking analysis, interaction with the platform, and interview. The investigation aims to uncover the perspectives of computer engineering students as they encounter a low-code platform for the first time, leveraging concurrent eye-tracking data to gain insights into their focal areas, the patterns that emerged in their approaches to tasks, and the elements that captured their attention. The findings suggest that students demonstrated efficient and swift recognition skills, showcasing various patterns in their task approaches, unveiling a spectrum of strategies and preferences. Interviews conducted post-interaction unveiled positive sentiments, with the majority acknowledging the low-code platform's effectiveness in minimizing application development time. Notably, ease of use emerged as a prominent aspect, with a substantial number finding the platform exceptionally user-friendly.

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Figure 1: Generated phrases across the Valence-Arousal space, from left to right 𝑉 + 𝐴 +

Serious Games have proved to have instructional potential due to their ability to present realistic simulations of real-life situations. In this study, a serious game called “Galaxy Solutions” was developed. This game simulates all the stages of the recruitment process. It starts when the player is searching for vacancies and submitting applications, continues to the interview process, and concludes at the last stage, in which a company named “Jupiter Solutions” hires the player. Consequently, new challenges unfold in the working environment. The main objective of this game is to help graduates acquire basic interview skills and be aware of the whole process by making the learning experience more enjoyable and engaging. Throughout the game, the player must make decisions through multiple-choice actions and dialogue, and all these decisions affect the character's events in the future. The game was evaluated by 105 students, and it was found usable by all the students, regardless of their success level in the game, and had a statistically significant learning effect, as the pre-posttest analysis revealed.

The text’s legibility can dramatically influence any device’s usability, and a wealth of research has examined the ideal font characteristics for various displays regarding legibility and readability. However, mobile devices have an additional factor that influences viewing conditions; their greatest strength, i.e., portability, is their biggest weakness in this regard. Furthermore, the freedom to use the device in diverse situations and positions (sitting, standing, in transit, or while waiting in line) can influence various facets related to legibility, such as the user’s holding position, operating style, and the environment’s light directed to the phone. The application developed aims to maintain user-preferred text font size -in all typical distances that users operate their phones- by automatically adjusting the font size according to the distance between the user and the device by using the device’s camera to calculate the distance in real-time. A two-part experiment (n = 34) revealed that the application scored an excellent usability score while the visual landmarks used showed a promising start at addressing an issue related to our approach.

Anxiety is prominent among university students and can cause many problems in students’ mental life. It is more important than ever to promote positive mental health in young people in a way that is understandable, reliable, and accessible. The PLAY learning environment was created to help students deal with their anxiety. Students can decide to either play a game scenario that simulates a stressful situation -in the context of academic life- and learn by doing or participate in an anonymous virtual counseling session and discuss their anxiety issues with a counselor. This paper examines whether such an environment can increase anxiety awareness and whether it helps students develop coping mechanisms. It also explores whether a virtual world is a proper medium to deal with anxiety issues. The paper presents the results from the evaluation from students from the Computer Engineering and Informatics Department of the University of Patras that offered early feedback on the PLAY environment. Regarding anonymous counseling, we present our findings concerning the viability of online counseling in a 3D virtual environment.

This paper presents a serious game that has been developed for programmers aiming to analyze and examine the effectiveness and the perceived usability of two different game interfaces. This game presents a drag-and-drop interface and a classical typing interface and towards this approach, four different versions of the same game were developed. Each version of the game focuses on either creating a part of code or debugging (finding the errors in the code provided). The game enables the players to advance their programming skills and computational thinking by engaging them in problem-solving activities during the gameplay. This paper provides insight and focuses on the evaluation of different interfaces in a serious game that is developed for programmers and targets fundamental programming concepts.

Effective teaching of concepts related to human computer interaction (HCI) requires introduction of the core paradigms as well as the design and evaluation methodologies to the learners. In this paper, we investigate the learning effectiveness of a tool-mediated learning activity to support instruction of established human performance models, namely the Keystroke Level Model (KLM) and Fitts’ law, and their application in web form design practice. The tool, named Keystroke Level Model Form Analyser (KLM-FA), supports learning through exploration by providing step-by-step tracing of the KLM modelling for any web form filling task. KLM-FA can be used in modelling exercises of either online or offline web forms according to different interaction strategies or users’ characteristics. Three pretest-posttest studies involving 52 students in total enrolled in computer science curricula with different education delivery methods (campus-based, blended learning, distance learning) and levels (undergraduate, postgraduate) provide evidence for the effectiveness of the proposed learning activity. In all three studies, it was found that the KLM-FA activity had a significant positive effect on students’ learning gain. In addition, students rated their perceived educational experience and KLM-FA usability as rather high. Content analysis of students’ comments also found that KLM-FA is an educationally valuable and usable tool.

Serious games play an important role in an individual's training and have been used for many educational purposes. In the context of this work, an educational game was developed which is called “My life as a software engineer” and focuses on technological as well as ethical dilemmas that software engineers may face during their careers. This game was used as an educational tool for the “Software Engineering” course in the Computer Engineering Department of the University of Patras. By playing this serious game, students had the opportunity to encounter situations and challenges related to the software engineering work environment. The game was found usable by the students and had a statistically significant learning effect as revealed at the pre-test and the post-test analysis. The data analysis also showed gender differences for usability as perceived by the students.

This paper describes the design and delivery of a postgraduate course on “Design and Evaluation of Interactive Systems”, part of an M.Sc. program on Human-Computer Interaction jointly offered by the Computer Engineering and Informatics Department and the Department of Electrical and Computer Engineering. This course was initially intended to use the flipped classroom model but was shifted online due to the COVID-19 lockdown imposed during the Spring 2020 semester. The paper discusses student attitudes towards the online flipped classroom model and draws preliminary conclusions on the advantages and limitations of the approach. Qualitative and quantitative assessment data indicate a positive overall students' perception of the online flipped classroom model.

HCI researchers and practitioners are increasingly using physiological data to measure User eXperience (UX) parameters. The dynamic nature of physiological data offers a continuous window for an in-depth understanding of users’ interaction experience. However, in order to be truly informative, physiological signals need to be linked to users’ interaction experience aspects, such as their emotional states, in a systematic and efficient way. Studies have shown that skin conductance is a physiological signal highly associated with stress. The main purpose of this paper is to present the validation study of our proposed stress detection mechanism which is integrated into a software named PhysiOBS. PhysiOBS is an observation analysis tool that can be used in the post-study analysis phase. PhysiOBS uses nonspecific skin conductance responses (NS-SCRs) in order to auto-report time periods that are probably associated with a problematic interaction. PhysiOBS can also combine multiple data sources. Hence, UX evaluators are able to further investigate a recorded session in order to reveal additional interaction flaws. The integrated stress assessment mechanism, which uses four trained classifiers, can be applied in the reported periods (auto/expert-reported) in order to classify them as stress or non-stress. For the purpose of the validation study, 24 users were recruited in order to participate in a lab experiment. Results showed that our stress assessment mechanism supports UX evaluators by accurately identifying stressful regions within an interaction scenario.

This paper presents a case study on using different input modalities in the perspective of a more natural way of interaction. The use of hand gestures and voice commands in a learning environment compared to the conventional ways of interaction is considered a significant parameter for the users' experience. This study investigates the correlation between the learning styles of a number of participants with the input modality being used. To conduct the study, an application which provides different ways of interaction was designed, developed and utilized. The results have shown that the 2-D motion device was the most prominent, as far as time of completion was concerned, because the users were more familiar with it. On the contrary, the natural ways of interaction were proven to be the most exciting by all participants. It is recorded that the natural way of interaction impels learners to participate and increases their motivation and engagement in learning activities.

This paper presents an on-line three-dimensional virtual world learning environment that has been developed aiming to contribute to the improvement of Information Security issues awareness. This learning environment simulates a number of information security threat scenarios, presented to users as games, selected by users as the most interesting ones. The environment enables students to experience the risks, be educated about them and combine skills and knowledge to overcome them, without exposing themselves and their data to real risk. This paper provides insight and focuses on the learning process and the learning outcomes of using this three-dimensional virtual world learning environment into a formal university education process for computer engineering students.

Massive Open Online Courses (MOOCs) are becoming widely spread and recent years have seen a substantial research interest on this topic. MOOCs are mediated by software platforms that need to meet specific non-functional requirements, such as usability. The goal of this paper is to investigate the usability of three popular MOOC platforms: edX, Coursera and Udacity. To this end, a study combining experimental and inquiry usability evaluation methods was conducted. Thirty-one participants were asked to perform five typical tasks in the evaluated MOOC platforms. Study results showed that Coursera was perceived to be significantly more usable compared to both edX and Udacity. In addition, interaction efficiency was significantly higher while using Coursera compared to Udacity. No significant effect of MOOC platform on participants' interaction effectiveness and perceived task difficulty was observed.

This paper presents a taxonomy of design guidelines for robot teleoperation developed from a focused literature review of robot teleoperation. A list of user interface design guidelines was assembled, open card sorting and a focus group were used to classify them, and closed card sorting was employed to validate and further refine the proposed taxonomy. The initially obtained set of 70 guidelines is grouped into eight categories: platform architecture and scalability, error prevention and recovery, visual design, information presentation, robot state awareness, interaction effectiveness and efficiency, robot environment/surroundings awareness, and cognitive factors. Agricultural robots were used as an application case study for implementation and field evaluation. The proposed guideline taxonomy was used heuristically to evaluate the usability of an existing user interface of a teleoperated agricultural robot.

Personal Learning Environments are used more and more by the academic community. They can coexist with formal courses as a communication and collaboration channel. In this paper, an application of learning analytics into HOU2LEARN, a Personal Learning Environment set by Hellenic Open University is discussed. The present part of research focuses on the social network analysis as a branch of learning analytics, along with formal grading system. Since it is an ongoing research, this paper presents the preliminary results of the study of the correlation between the social network metrics and the formal grades, through a test case course, the PLH42.

The objective of this study is to discuss how software usability flaws may cause a significant increase in mouse movements and, as a potential side effect, may even affect users' health. During the literature review, this article examines the potential relationship between mouse movement and musculoskeletal disorders of the upper extremity, based on studies from medical sciences. Subsequently, in the main part of the present study, three software products were selected that had at least one usability flaw related to extra mouse movement (the selection of the software was made out of over 20 software programs that had been evaluated in our Software Quality Assessment Laboratory). For these products, all additional mouse movements were measured, involving actual users in various settings and computer configurations. The findings showed that even a single usability flaw may increase mouse movement to a magnitude of between 3.6 and 4.7 m/h. The article concludes that the role of software engineering is to focus on software usability as well, taking into account that a user friendly graphical user interface (GUI) which is able to eliminate unnecessary mouse movement may also eventually contribute to the reduction of fatigue and discomfort, caused by musculoskeletal disorders.

After the debunking of some myths about why P2P overlays are not feasible in sensornets, many such solutions have been proposed. None of the existing P2P overlays for sensornets provide "Energy-Level Application and Services". On this purpose and based on the efficient P2P method presented in [16], we design a novel P2P overlay for Energy Level discovery in a sensornet, the so-called ELDT (Energy Level Distributed Tree). Sensor nodes are mapped to peers based on their energy level. As the energy levels change, the sensor nodes would have to move from one peer to another and this oparation is the most crucial for the efficient scalability of the proposed system. Similarly, as the energy level of a sensor node becomes extremelly low, that node may want to forward it's task to another node with the desired energy level. The adaptation of the P2P index presented in [16] quarantees the best-known query performance of the above operation. We experimentally verify this performance via an appropriate simulator we have designed for this purpose.

This paper describes our experience with introduction of synchronous collaborative problem solving activities in the frame of a distance learning computer science undergraduate course of the Hellenic Open University (HOU). Groups of students worked collaboratively at a distance in order to build a flowchart of an algorithm to a given problem. The technological and organization issues involved, the first findings of analysis of peer student interaction during this study, as well as some general implications for distance education are discussed.