Task Design: Its Impact on Usability Testing

Usability testing is a technique for measuring a system\´s usability. It consists of a number of variables such as tasks, number of users, evaluators, and other elements. This paper explores the proposal that task design can seriously influence the usability testing results. It describes how two different types of task affect results. The types explored are structured tasks and uncertain tasks. Each type of task seems to discover different types of problems. In addition, in this research, the magic number of "five users" fails to achieve the promised 85% of usability problems^.