Summary The positions of 129 14 to 19?year?old students on two fundamental cognitive styles dimensions (Wholist?Analytic and Verbal?Imagery) were assessed. They then received, by random allocation, one of three versions of a computer?presented instruction package on home hot water systems. The versions differed in terms of their structure (large versus small step), advance organiser (absent or present), verbal emphasis (high versus low), and diagram type (abstract versus pictorial). Version 1 had large step, no organiser, high verbal content, and abstract diagram. (...) Version 2 had small step, no organiser, low verbal content, and pictorial diagram. Version 3 was identical to Version 2, except that an organiser in the form of an elaborated introduction was given in which all five topics were introduced and each section began with an overview and ended with a summary. There was a significant interaction between version and cognitive style in their effect on recall. The results were discussed in terms of their implications for instruction. (shrink)