Getting into a system: External-internal task mapping analysis

A task analysis technique, called ETIT analysis, is introduced. It is based on the idea that tasks in the external world must be reformulated into the internal concepts of a computer system before the system can be used. The analysis is in the form of a mapping between sets of external tasks and internal tasks. An example analysis of several text editing systems is presented, and various properties of the systems are derived from the analysis. Further, it is shown how this analysis can be used to assess the potential transfer of knowledge from one system to another, i.e., how much knowing one system helps with learning another. Several issues are briefly discussed.