When simulated environments make the difference: the effectiveness of different types of training of car service procedures

An empirical analysis was performed to compare the effectiveness of different approaches to training a set of procedural skills to a sample of novice trainees. Sixty-five participants were randomly assigned to one of the following three training groups: (1) learning-by-doing in a 3D desktop virtual environment, (2) learning-by-observing a video (show-and-tell) explanation of the procedures, and (3) trial-and-error. In each group, participants were trained on two car service procedures. Participants were recalled to perform a procedure either 2 or 4 weeks after the training. The results showed that: (1) participants trained through the virtual approach of learning-by-doing performed both procedures significantly better (i.e. p < .05 in terms of errors and time) than people of non-virtual groups, (2) the virtual training group, after a period of non-use, were more effective than non-virtual training (i.e. p < .05) in their ability to recover their skills, (3) after a (simulated) long period from the training—i.e. up to 12 weeks—people who experienced 3D environments consistently performed better than people who received other kinds of training. The results also suggested that independently from the training group, trainees’ visuospatial abilities were a predictor of performance, at least for the complex service procedure, adj R2 = .460, and that post-training performances of people trained through virtual learning-by-doing are not affected by learning styles. Finally, a strong relationship (p < .001, R2 = .441) was identified between usability and trust in the use of the virtual training tool—i.e. the more the system was perceived as usable, the more it was perceived as trustable to acquire the competences

A method for mapping and measuring users' mental models of the depth/breadth tradeoff

Understanding users' mental models can improve design and testing of interactive systems. Yet, the extraction of users' mental models and their representation are still a tough challenge. We addressed this question by focusing on how the depth/breadth tradeoff in web navigation structures is reflected in users' mental models. The approach presented here is based on gathering the data in an unlimited-hierarchy variation of card sorting technique and analyzing the results using hierarchic cluster analysis visualized with dendograms. We report a pilot study of our approach and compare the hierarchic cluster analysis and dendograms with ANOVA. The findings show significantly different perceptions of breadth versus depth in two different devices, a desktop computer and cellular phone. These findings are in contrast with findings of more traditional mental model assessment approaches, thus validating the necessity and the usefulness of the purposed new approach

Web navigation structures in cellular phones: The depth/breadth trade-off issue

One can browse the web with a variety of devices, including hand-held devices such as the cellular phone. The small screen of those devices poses some serious usability issues, one of which is the appropriate hierarchy depth of the web site. In this study, we empirically examined whether a broad navigation structure, which was found to be superior in regular screen-size platforms, also has an advantage for a small-screen device such as the cellular phone where it may require more movements and scrolling between screens of the same hierarchical level. Navigation times and success rates were measured for two search tasks in a mock web site that was built in two versions: one with a broad navigation structure and the other with a deep structure. Both structures were tested with cellular phone emulation and a standard desktop personal computer (PC). Results indicate that performance was better with the broad navigation structure for both the cellular phone and the PC. In addition, performance was better with the PC as compared to the cellular phone, and this difference was pronounced in the broad structure. The results are discussed in terms of the impact of device-independent characteristics of the hierarchy depth along with the theoretical account of increased working memory load, confusion and disorientation associated more with deep structures