Eye Tracking for Adaptive E-learning Usability

1. Ayuda GR15175. Junta de Extremadura. Fondos FEDER. Eye Tracking for Requirement Elicitation: Usability Validation of Adaptive E-learning Environments Marco Porta1, Juan Francisco Ortega Morán2,*, J. Blas Pagador2 and Francisco M. Sánchez Margallo2 1Dip. di Ingegneria Industriale e dell‟Informazione - Università di Pavia, Pavia, Italy 2,* Centro de Cirugía de Mínima Invasión Jesús Usón, Cáceres, Spain 1st International Workshop on Maturity of Web Engineering Practices (MATWEP 2018) June 5th, 2018 Cáceres (Spain)

2. Introduction RequirementsEngineering Definition Is the branch of software engineering concerned with the real world goals for, function of, and constraints on software systems. It is also concerned with the relationship of these factors to precise specifications of software behavior, and to their evolution over time and across software families Requirement Elicitation Is the procedure of gathering the requirements of a system from users Several authors have stressed the importance of Human-Centered Design and Usability for its success Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

3. Introduction Usability ISO 9241-210 definition the extent to which a system, product or service can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use Jakob Nielsen's definition a quality attribute that assesses how easy user interfaces are to use Assessment cannot be easily automated (if ever), due to the many subjective factors that come into play… Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

4. Introduction Objective We propose an approach to Requirement Elicitation, an integral part of RE, in which usability evaluations are carried out through simplified quantitative analysis procedures, based on eye tracking technology. Advantages • It can provide simple, objective, and partially automatable evaluations • Even software engineers and programmers with a limited experience in usability matters can potentially deal with interface design and user-related issues Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

5. Eye tracking and usability Eye tracking Eye movements occur as almost instantaneous saccades, followed by fixation periods • saccades  very fast (< 100 ms) • fixations  100 – 600 ms An eye tracker is able to follow users' eyes, to detect where they are looking at it measures how infrared light is reflected by the cornea and by the retina through the pupil Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

6. Eye tracking and usability Where are you looking at? Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

7. Eye tracking and usability The Tobii 1750 eye tracker • Non-invasive technology • Components: • screen • infrared emitters • videocamera • Corneal reflection of infrared light • Sampling rate: 50Hz Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

8. Eye tracking and usability Usability inspection through ET Typical procedures analysis of eye scan paths, hotspots, … Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

9. Eye tracking and usability Eye tracking allows to • analyse the level of user interest, content clearness, and content layout effectiveness • discover where users are supposed to find certain elements in an interface, and therefore validate initial design goals • extract typical metrics of usability, such as the number of fixations, their duration, their average duration, and the eye scanpath length. Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

10. Eye tracking and usability Eye tracking allows to Represent scanpaths, where gazeplotsare often employed graphical depictions of fixations, represented by circles with areas proportional to their duration and connected by straight lines indicating saccades Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

11. The need for simple usability evaluation tools Gaze-based Usability Inspector Tool - GUIT Gaze Recording Software Experiment definition Result files (gaze data) GUIT (Gaze-based Usability Inspector Tool) Simplified indication of interface problems, "user behaviour", etc. Goals, constraints (defined for the interface being inspected) Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

12. The need for simple usability evaluation tools GUIT - Overview Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

13. The need for simple usability evaluation tools GUIT – AOIs and Grid Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

14. The need for simple usability evaluation tools GUIT – Parameters of the Analysis Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

15. The need for simple usability evaluation tools GUIT – Parameters of the Analysis Fixation time - Eye color Absolute analysis: • E.g. High = 25%, Low = 10% • Green eye if the sum of all durations of all fixations of all selected testers (within the considered region) reaches at least the 25% of the sum of the durations of all fixations (of all selected testers) within the page • The eye will be orange if the percentage is between 25% and 10% • The eye will be red if the percentage is less than 10% Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

16. The need for simple usability evaluation tools GUIT – Parameters of the Analysis Fixation time - Eye color Relative analysis: • E.g. High = 90%, Low = 45% • The average "time per pixel" spent by each tester on the page is multiplied by the area of the region  R • R is compared with the total fixation duration of selected testers in the region • Green eye if the duration reaches at least 90% of R • Orange eye if the percentage is between 45% and 90% of R • Red eye if the percentage is less than 45% of R Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

17. The need for simple usability evaluation tools GUIT – Parameters of the Analysis First fix. time – Clock color • E.g. High = 50%, Low = 20%, First view = 20% • Green clock if, for each selected tester, considering the first 20% portion of the time s/he has spent on the page, the sum of durations of all fixations in those intervals reaches at least 50% of the sum of durations of all these intervals • The eye will be orange if the sum is between 50% and 20% • The eye will be red if the sum is less than 20% Analogous considerations for the Last fixation time… Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

18. The need for simple usability evaluation tools GUIT – Text AOIs Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

19. The need for simple usability evaluation tools GUIT – Dominant Scanpaths Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

20. The need for simple usability evaluation tools GUIT – InterpageAnalysis Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

21. GUIT to requirements validation in RE ISO 9241 (Part 210) ergonomic requirements applied to user interfaces, an effective human-centered RE process should be sufficiently: • “Formal”, to avoid ambiguities in the specification of requirements and interpretation of results. • “Simple”, to enable “non-experts” to define and carry out usability tests, and to easily understand results. • “Objective”, to allow clear-cut interpretations of results Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

22. GUIT to requirements validation in RE GUIT on a preliminary, prototype version of a system, fulfill the three points: • “Formal” Requirements can be more formally specified in terms of steps that should be followed when performing a specific task using an interface. • “Simple”  It is possible to easily define areas of interest in correspondence of key regions in the interface and the presentation of results in the form of icons. • “Objective” Outputs of GUIT derive from objective eye parameters and actual user actions Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

23. GUIT-based validation of adaptive e-learning environments for MIS training • Flexibility in time, place and access to content • Progress at the most appropriate speed e-learning • Lack of emotional contact between teachers and learners • Detect difficulties in students’ learning processes, as well as identifying their cognitive stress or fatigue Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

24. GUIT-based validation of adaptive e-learning environments for MIS training Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

25. GUIT-based validation of adaptive e-learning environments for MIS training Eye tracking technologies can extract metrics from the eye movements and gaze behaviour with two aims: • to obtain the learner’s cognitive state, tiredness and emotions to adapt and customize the e-learning environment. • to perform its usability validation with the GUIT software. Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

26. Conclusions • We have proposed an approach based on eye tracking for simple, formal and objective assessment of the usability of user interfaces, in the context of Requirement Elicitation, extremely important for Requirements Engineering • The presented approach could be used for the usability validation of the increasingly used e-learning environments for MIS training, which could also exploit eye tracking to adapt and customize user’s learning thanks to the detection of their emotions and cognitive states by eye tracking technologies. Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

27. Conclusions • GUIT aims at simplifying the interpretation of eye-tracking-based usability studies Especially for non-experts… • Dealing with the large amount of numbers produced by even simple quantitative eye tracking experiments is usually a complex task the icon-based approach of GUIT, which "discretizes" the results about viewing, reading and comprehension levels into three possible outcomes, provides an immediate and intuitive feedback Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

28. Creation of bridges from the theory to the practice • The proposed approach allows to simplify the exploitation of eye tracking data, that usually needs detailed analyses by experts • Thanks to described approach, Requirement Elicitation from gaze behavior can become a procedure within the reach of (almost) everyone Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

29. Problems of knowledge transfer and lessons learned • Knowledge transfer from experts to novices is always a critical issue, in any context; easy to understand procedures, that reduce misinterpretations as much as possible, are the best solution to obtain reliable and cost-effective results (although, sometimes, the precision may be limited); • The proposed system has not been thoroughly tested to date, but preliminary informal experiments have shown good acceptance by non-expert users Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

30. Feedback for improving Web Engineering techniques, methods and approaches • The described solution can potentially improve Web Engineering techniques by enhancing preliminary (Web) interface evaluation, thus helping in requirement elicitation; • While interface assessment is often considered only in the context of usability, its correct implementation is very important also for Requirements Elicitation: the objective feedback provided by eye tracking data can greatly improve the whole Requirements Engineering procedure Ayuda GR15175. Junta de Extremadura. Fondos FEDER.

31. Eye Tracking for Requirement Elicitation: Usability Validation of Adaptive E-learning Environments Thanks! For further information: marco.porta@unipv.it jfortega@ccmijesususon.com Ayuda GR15175. Junta de Extremadura. Fondos FEDER.