Cognitive overheads and prostheses
Patricia Wright · 1991
There are many criteria for evaluating hypertext.Adequacy and cost effectiveness are perhaps the most obvious flom the producer's perspective additional criteria are important for users.Examination of the limitations of various assessment criteria highlights the twin issues of the cognitive costs and benefits experienced by people using hypertext as part of some other task.Many interface characteristics can contribute to readers' cognitive overheads.There is evidence that even changing screens to access information only a click away can impair memory processes.Fortunately, because hypertext are computerbased, readers can call upon a variety of aids to support their cognitive activities, particularly memory and planning processes.The novelty of some of these prostheses raises questions about the literacy skills that hypertext readers may need.Studies of factors influencing readers' strategic decisions about using memory aids are discussed, together with their implications for hypertext design.It is concluded that hypertext evaluation requires a richer understanding of the cognitive entailments of working with information.But hypertext, having highlighted the problems of cognitive costs, have the potential for offering readers the means of reducing these overheads not just for hypertext use but for many tasks that involve working with information.