EVALUATING AND IMPROVING THE USABILITY OF A USER MANUAL

This research deals with user-testing as a means to improve the usabil ity of a user manual: In Study 1 we analysed the effects of three diff erent methods for user-testing a commercial user manual to a patient a dministrative system. Thirty nurses read the manual and noted difficul ties found by either (1) making underlinings, (2) writing questions, o r (3) verbalizing their comments aloud. Underlinings were more associa ted with difficult words or concepts, and question writing with broade r content issues. Comments verbalized aloud produced the greatest vari ety of information and the greatest number of comments. In Study 2 we analysed the effects of rewriting the user manual on the basis of the results from the user-tests performed in Study 1 and some general writ ing principles. The modified manual group spent significantly less tim e (21% less) on the tasks, issued significantly fewer ineffective comm ands and made significantly fewer obstructive errors, compared to the original manual group. However, no differences were found with respect to error recovery. These results suggest that user-testing by means o f the investigated methods can be an important means to enhance the us ability of user instruction manuals.