Abstract
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.