Elderly people seem to encounter more problems than people from other age groups do, when using consumer electronics products and their accompanying manuals. This may be due to the absence of some kinds of information. In this study the effects of the absence of different information types in instructions on action performance were explored for different age groups. Younger (aged 20–30 y.) and elderly (aged 60–70 y.) participants installed a VCR with the help of the manual, while working aloud. The absence of goal information, consequence information and identification information in the instructions proved to have a negative effect on task performance, especially for the elderly participants. When one of these information types was missing in the instructions, the elderly performed more actions incorrectly than when the information was stated explicitly.

The aim of the study was to map the influence of reading task and text format on reading results with an online text. To this purpose, an experiment performed by S. Gordon et al. (1988) was replicated and enhanced. In four conditions, subjects were given a reading task (summarize or answer specific questions) and an online text (linear or hypertext format). In all conditions, both text and task were administered through the World Wide Web, After the subjects had completed their reading, all were given the same assignment: make a summary and answer specific questions. No significant main effects of the independent variables (format and task) were found on the performance of the subjects. There proved to be a significant interaction effect, however, on the completeness of the summaries. The most thorough summaries were written by subjects who were told before the experiment that they would have to summarize the text, and who were presented with the text in a linear version. As far as reading time was concerned, there was a significant difference between the format conditions: reading the text in linear format took more time than reading the text in hypertext format.