Evaluating and improving the usability of a user manual

This research deals with user-testing as a means to improve the usability of a user manual. In Study 1 we analysed the effects of three different methods for user-testing a commercial user manual to a patient administrative system. Thirty nurses read the manual and noted difficulties found by either (1) making underlinings, (2) writing questions, or (3) verbalizing their comments aloud. Underlinings were more associated with difficult words or concepts, and question writing with broader content issues. Comments verbalized aloud produced the greatest variety 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 writing principles. The modified manual group spent significantly less time (21% less) on the tasks, issued significantly fewer ineffective commands 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 of the investigated methods can be an important means to enhance the usability of user instruction manuals.