Software Interface Evaluation: Modeling of Human Error

Abstract

The purpose of this study was to use a human error model to evaluate a commercially available Macintosh-based graphics application based upon the frequencies and types of mistakes occurring during users' performance of designated tasks. The occurrence of high frequencies of knowledge-based and rule-based mistakes during the learning of an interface element would indicate that the element requires evaluation and possible redesign.

This study involved five participants, all of whom were students at Texas A&M University. The participants were experienced Macintosh users with no experience using Macintosh graphics software. The graphics environment of interest was MacDraw II® 1.0 Version 2 (Schutten, Goldsmith, Kaptanoglu, and Spiegel, 1988). Ten drawings created with the program were used to examine participants' cognitive levels and types of errors made throughout the process of familiarizing themselves with this program. The first drawing was created to exemplify simple figures created with the graphics tools in the program to illustrate shading. The second through tenth drawings incorporated these figures in several arrangements. All drawings incorporated eight tools (or tasks), and each tool was used only once in each drawing. The results indicated significant differences in frequencies of error types, frequencies of errors between tasks and frequencies of errors between trials. There were also interactions between trial and error, and task and error.