Trevor Barker

Investigation into effective navigation in desktop virtual interfaces

The study reported in this paper is concerned with understanding and providing solutions to commonly reported navigation and orientation issues in virtual 3D desktop environments. An experiment was performed to investigate some of these issues. Twelve subjects performed simple tasks within a virtual desktop environment using navigational tools developed specifically for the research. Tasks were based on locating information in simple environments. Time to complete tasks, ability to remember the locations of information within the environment and user attitude were measured and recorded, along with several other important variables described in the paper. Performance on tasks and attitude to the environments was found in many cases to be related to the navigational tools used within the environments. The results demonstrated that constraining and guiding the navigation produces more effective navigation and orientation. It was found that the use of a 3D map to assist navigation was most effective in terms of time to perform tasks (p<0.01). The development of the navigational tools, the method used in the experiment and the results of the experiment are reported in this paper. The paper concludes with a discussion on how the findings of this research relate to the solution to general navigational and orientational issues in 3D virtual environments.

The Use of a Co-operative Student Model of Learner Characteristics to Configure a Multimedia Application

This paper describes an investigation into the ways in which learning using a multimedia application can be supported and enhanced by means of a simple co-operative student model of learner characteristics. This paper reports the design, implementation and evaluation of an individually configurable multimedia learning application, based upon such a model.A multimedia learning application was developed that presented information differentially based upon the individual characteristics of learners, held in the student model. The characteristics employed in the model were language level, cognitive style, task and question levels, and help level. Small groups of learners followed the multimedia course in learning centres located in colleges in the UK. A Grounded Theory study was carried out in order to understand the many and complex interactions that took place between learners, tutors and the learning environment.Stages in the Grounded Theory method are described and some qualitative data is presented. It was possible to conclude from these, that the quality of learning for individuals was improved by the use of the co-operative student model. Quantitative data is presented to support this view and where possible, to relate performance on the multimedia learning application to the student model configuration.

A computer adaptive test that facilitates the modification of previously entered responses : An empirical study

In a computer-adaptive test (CAT), learners are not usually allowed to revise previously entered responses. In this paper, we present findings from our most recent empirical study, which involved two groups of learners and a modified version of a CAT application that provided the facility to revise previously entered responses. Findings from this study showed that the ability to modify previously entered responses did not lead to significant differences in performance for one group of learners (p>0.05), and only relatively small yet significant differences for the other (p<0.01). The implications and the reasons for the difference between the groups are explored in this paper. Despite the small effect of the modification, it is argued that this option is likely to lead to a reduction in student anxiety and an increase in student confidence in this assessment method.

Evaluating security and usability of profile based challenge questions authentication in online examinations

Student authentication in online learning environments is an increasingly challenging issue due to the inherent absence of physical interaction with online users and potential security threats to online examinations. This study is part of ongoing research on student authentication in online examinations evaluating the potential benefits of using challenge questions. The authors developed a Profile Based Authentication Framework (PBAF), which utilises challenge questions for students’ authentication in online examinations. This paper examines the findings of an empirical study in which 23 participants used the PBAF including an abuse case security analysis of the PBAF approach. The overall usability analysis suggests that the PBAF is efficient, effective and usable. However, specific questions need replacement with suitable alternatives due to usability challenges. The results of the current research study suggest that memorability, clarity of questions, syntactic variation and question relevance can cause usability issues leading to authentication failure. A configurable traffic light system was designed and implemented to improve the usability of challenge questions. The security analysis indicates that the PBAF is resistant to informed guessing in general, however, specific questions were identified with security issues. The security analysis identifies challenge questions with potential risks of informed guessing by friends and colleagues. The study was performed with a small number of participants in a simulation online course and the results need to be verified in a real educational context on a larger sample size.

An empirical study of user preference and performance with UML diagrams

Elicitation and validation of user requirements depend, to a large extent, on the effectiveness of the tools and techniques used as a vehicle for discussion between developers and users during the requirements process. This effectiveness may, in turn, be influenced by user preference for a particular approach or requirements technique. This paper describes a study that was carried out to investigate the relationship between user preference for sequence or collaboration diagrams in UML, with their accuracy in understanding information contained in the diagrams. Results showed that user preference for one of the two diagram types before carrying out the task was not reflected in improved performance with that type of diagram compared with the other. However, after carrying out the task, user statements about which type of diagram they preferred working with were matched by improved performance with that type of diagram.

How Group Working Was Used to Provide a Constructive Computer-Based Learning Environment

In this paper, the development and evaluation of a computer based multimedia learning environment capable of supporting group worldng is reported. The application developed in this study was used in a Further Education (FE) college by tutors and students following a catering course. Learners engaged in the application, performing a range of tasks, based on group working and role playing both on and off-computex. Although no significant difference was found between performance in individual and group work it was found that learners and teachers valued the approach used and performed at least as well on the course than in previous years.

An automated feedback system based on adaptive testing: extending the model

Abstractâ??The results of the recent national students survey (NSS) revealed that a major problem in HE today is that of student feedback. Research carried out by members of the project team in the past has led to the development of an automated student feedback system for use with objective formative testing. This software relies on an â??intelligentâ?? engine to determine the most appropriate individual feedback, based on test performance, relating not only to answers, but also to Bloomâ??s cognitive levels. The system also recommends additional materials and challenges, for each individual learner. Detailed evaluation with more than 500 students and 100 university staff have shown that the system is highly valued by learners and seen by staff as an important addition to the methods available. The software has been used on two modules so far over a two year period

An empirical study of factors that affect user performance when using UML interaction diagrams

During the requirements process it is of key importance that all representations used are clearly understood by those who must use them. Therefore it is essential to ensure that those representations are presented as effectively as possible. The research reported in this paper relates to an empirical study carried out to investigate factors which might affect user performance when using UML interaction diagrams. Several variables were investigated in the study; these were identified from the related literature and earlier research by us as being important in understanding interaction diagrams. The independent variables investigated in the study were diagram type, user pre-test and post-test preference, individuals cognitive style, text direction, scenario type and question type. Time taken to formulate the correct answer was the dependent variable used as the measure of performance. Statistical analysis of data showed significant differences for several variables, including diagram type, preference, and scenario type (p<0.05).

User Preference and Performance with UML Interaction Diagrams

During the requirements process, it is of key importance that all representations used are clearly understood by those who must use them. Therefore it is essential to ensure that those representations are presented as effectively as possible. User preference is one area that may influence the effectiveness of the representations presented. This paper describes a study that was carried out to explore the relationship between user preference for UML sequence and collaboration diagrams. Results show that participants who preferred sequence diagrams showed improved performance when using sequence diagrams. This was true for preferences expressed both before and after the task. However, participants who did not prefer sequence diagrams showed an overall improved performance for both types of diagram over the group that preferred sequence diagrams

Smartphone Application Usability Evaluation: The Applicability of Traditional Heuristics

The Heuristic Evaluation method has been popular with HCI experts for over 20 years. Yet, we believe that the set of heuristics defined by Nielsen in 1994 needs to be modified prior to the usability evaluation of smartphone applications. In this paper, we investigate the applicability of each of Nielsens traditional heuristics to the usability evaluation of smartphone applications following an analysis of 105 peer-reviewed papers. It is anticipated that this work might benefit HCI practitioners, educators and researchers as they attempt to define usability heuristics for smartphone applications. This set of heuristics, once defined, could enable the discovery of usability issues early in the smartphone application development life cycle, while continuing to be a discount usability engineering method as originally defined by Nielsen.