The effects of positional constancy on searching menus for information

Abstract

This experiment is another example of how the software design of a man-display interface can affect the performance of a VDT user (Granda et al., 1982). This study demonstrates a clear performance advantage in searching for screen-presented information in a multiple screen interface, when that information is present in a positionally constant manner, as compared with a positionally nonconstant presentation. Furthermore. the current study documents the emergence of this advantage over time. Positional nonconstancy is shown to have a performance cost in increased time and eye movements. This cost would almost certainly have a negative impact on the usability of a software application. Note that the current study required subjects to view only eighty screens, in about one hours time. Thus, this study may provide only a conservative estimate of this cost.