Abstract
People tend to feel difficulty in working on displays rather than on paper. We suppose that rather long memory holding time, in our short-term memory, requested by working on a display is a dominant reason of difficulty with complicated tasks on a display. That's because working on a display, on which we often have to watch multi sheet of documents alternatively, generally force us longer memory holding time than when we are working on multi sheet of real papers. Subjects were requested to process tasks which need cross-reference between multi pages of documents with different viewing conditions of the pages;parallel showing and alternate showing of the multi pages. The results of measurement showed longer working time in alternate showing. We regard the longer working time in the alternate showing as a result of shortage of short-term memory, which was more eagerly requested by the alternate showing conditions.
