Software Engineering by Pearson

196 Software Engineering

It is usually a good idea to avoid mixing these levels. For example, consider a word processor ap-

plication that allows users to select multiple (range of) text characters of a document fi le. However, the

so ware usually does not allow selection of text characters and document fi les at the same time. One way

to do this is to ‘dim’ the selection that is not applicable in the current context.

Sometimes users may shi from one context to another. For example, they may be working in a par-

ticular task, when a dialog-box pops up asking them for confi rmation of an action.  is sudden shi of

context may confuse them.