Abstract
Anecdotal evidence suggests that using a restricted language called Simplified English (SE) to write procedural documents is the best method to accommodate specific audiences. Providing empirical data to prove or disprove this hypothesis is the point of the experiment reported here. This study examined the effect of document type (SE versus non-SE), passage (Procedure A versus Procedure B), and native language (native versus non-native English speakers) on the comprehensibility, identification of content location, and task completion time of procedure documents for airplane maintenance. This research suggests that using SE significantly improves the comprehensibility of more complex documents. Further, readers of more complex SE documents can more easily locate and identify information within the document. For the documents tested in this experiment, the SE and non-SE documents took essentially the same amount of time for subjects to read and complete the test. Finally, while the difference between native and non-native English speakers could not be tested statistically because of extremely different cell sizes, the comprehensibility and content location scores for the native and non-native speakers appear to be quite different, with the non-native speakers benefiting from SE more than the native speakers.