How interface design determines Who has difficulty learning to use a text editor

In previous studies two background characteristics of computer novices were consistently correlated with their success in learning to use a line-based computer text editor. Older people and those who scored low on a standard test of Spatial Memory had more difficulty than younger people and those with higher Spatial Memory test scores. In the present study, we observed computer novices as they learned to use a screen-based editor, which presumably reduced spatial memory load. Contrary to expectations, performance using a screen-based editor was again strongly correlated with Spatial Memory test scores. However, the correlation between performance and subjects' age was significantly reduced. Overall, subjects were able to perform the same text editing exercises almost twice as fast using the screen editor compared to subjects in previous experiments using the line editor. These results are discussed in terms of the different cognitive demands placed on users by line and screen text editors.