Creating Usable Wordless Instructions for Performing Complex One-Time Tasks: Effects of Violating the Rules

Abstract

We have developed design rules for diagrammatic instructions for initial setup, basic maintenance and troubleshooting (i.e., clearing paper jams) tasks. The study reported here evaluated these rules. Four groups of novice users cleared paper jams in a laser printer using one of four different diagrammatic instructions. Diagrams presented to the first two groups all followed the rules but differed in the number of actions per diagram (one verses 3-4). The remaining groups' instructions contained diagrams that violated one or more rules. Instructions that followed the diagram design rules resulted in no errors. Diagrams that prevented users from correctly identifying the location of a subtask resulted in the most severe errors. Other rule violations resulted in fewer errors of lesser severity so if users were shown the general location of the problem they could perform a subtask. Times to complete each subtask were similar unless the location rule was violated.