INVARIANT USER INTERFACES

In this article the term invariant user interface is introduced for a generic, stable backbone of all user interfaces, which contain a set of predefined elements and rules to build complex interactive systems. Invariant user interfaces specify fix points in using information systems. We argue that in interfaces of complex software applications such fix points are increasingly necessary. Based upon psychological assumptions and results of human computer interaction (HCI) studies, the necessity and benefits of invariance is shown, among others increased efficiency, enhanced reliability of use and decreased cost of software ownership. In this article invariance properties of state-of-the-art user interfaces are summarized, and a simple interaction model is introduced. Types and limits of invariance is defined using this model, and a set of fundamental criteria is characterized that invariant interfaces must meet

A complex physiology-based empirical usability evaluation method in practice

This paper outlines the INTERFACE usability evaluation methodology developed by researchers of our department. It is based on the simultaneous assessment of Heart Period Variability (HPV), Skin Conductance (SC), and other data. One of the highlights of this methodology is its capability to identify quality attributes of software elements with a time-resolution of only a few seconds: in particular cases it can assess 2- or 3-second events. The Department of Ergonomics and Psychology at the Budapest University of Technology and Economics carried out applied research projects assessing very various software. After these, we can show different types of typical software problems identified by our method. The method of analysis allows us not only to decide what types of problems are significant to the users; however, on the other hand, the method allows us to decide, to what extent the found problems and their assessed severity concern all the users in general, or how these things depend on the type and characteris tics of the users

Methodological Challenges in Eye-Tracking based Usability Testing of 3-Dimensional Software – Presented via Experiences of Usability Tests of Four 3D Applications

Eye-tracking based usability testing and User Experience (UX) research are widespread in the development processes of various types of software; however, there exist specific difficulties during usability tests of three-dimensional (3D) software. Analysing the screen records with gaze plots, heatmaps of fixations, and statistics of Areas of Interests (AOI), methodological problems occur when the participant wants to rotate, zoom, or move the 3D space. The data gained regarded the menu bar is mainly interpretable; however, the data regarded the 3D environment is hardly so, or not at all. Our research tested four software applications with the aforementioned problem in mind: ViveLab and Jack Digital Human Modelling (DHM) and ArchiCAD and CATIA Computer Aided Design (CAD) software. Our original goal was twofold. Firstly, with these usability tests, we aimed to identify issues in the software. Secondly, we tested the utility of a new methodology which was included in the tests. This paper summarizes the results on the methodology based on individual experiments with different software applications. One of the main ideas behind the methodology adopted is to tell the participants (during certain subtasks of the tests) not to move the 3D space while they perform the given tasks at a certain point in the usability test. During the experiments, we applied a Tobii eye-tracking device, and after the task completion, each participant was interviewed. Based on these experiences, the methodology appears to be both useful and applicable, and its visualisation techniques for one or more participants are interpretable

A Content-Analysis Approach for Exploring Usability Problems in a Collaborative Virtual Environment

As Virtual Reality (VR) products are becoming more widely available in the consumer market, improving the usability of these devices and environments is crucial. In this paper, we are going to introduce a framework for the usability evaluation of collaborative 3D virtual environments based on a large-scale usability study of a mixedmodality collaborative VR system. We first review previous literature about important usability issues related to collaborative 3D virtual environments, supplemented with our research in which we conducted 122 interviews after participants solved a collaborative virtual reality task. Then, building on the literature review and our results, we extend previous usability frameworks. We identified twelve different usability problems, and based on the causes of the problems, we grouped them into three main categories: VR environment-, device interaction-, and task-specific problems. The framework can be used to guide the usability evaluation of collaborative VR environments