Design and evaluation of online multimedia maintenance manuals

In two experiments younger (18-25 years) and older (60-70 years) participants performed an information retrieval task in which they searched for the answers to questions in a hierarchical menu structure. Participants' movement speed, spatial ability, spatial memory, working memory capacity and reasoning speed were measured. Results showed older participants to be slower than younger participants on overall latencies on the information retrieval task. This slowing increases with each consecutive step in the menu structure. Regression analysis showed that movement speed, reasoning speed and spatial ability predicted the overall latencies accurately. Modelling the consecutive steps showed that latencies on the first selection are predicted by movement speed and reasoning speed. Memory and spatial measures are predictors for latencies on steps further into the menu structure only. This finding is consistent with increased slowing of older participants for later selections and suggests that deep menu structures are less suited for older users

Designing an on-line multimedia maintenance manual for a production environment

Maintenance in production environments is becoming increasingly more complex, as machines become more technologically advanced and need less maintenance. As a result, maintenance personnel face more difficult tasks but at the same time obtain less experience with them. In this context, on-line multimedia manuals were thought to give better support than paper manuals. Three prototypes were designed and tested in an industrial environment, to find out how to design an on-line manual that indeed is better than a paper manual. The evaluation of the first prototype showed that maintenance engineers encountered serious problems with the first prototype of an on-line multimedia manual, as they omitted crucial steps in the task. The literature states that this is a typical problem in the execution of maintenance procedures. Based on findings in the literature, several design guidelines were formulated and applied to a second prototype to reduce the omission of steps in the procedures. This prototype was also evaluated by users.The third prototype addressed another problem encountered in the second evaluation. The people using the prototype experienced problems with switching between the on-line manual and the machine controls. The users made mode errors. To solve this, a third prototype was designed and tested. The results indicate that combining the on-line manual and the machine control into one user interface may prevent mode errors