The purpose of task analysis is to describe tasks, and more particularly, to identify and characterize the fundamental characteristics of a specific activity or set of activities. According to the Shorter Oxford Dictionary, a task is “any piece of work that has to be done” and is generally taken to mean one or more functions or activities that must be performed to achieve a specific goal. Since a task always is a directed activity, simply speaking of activities and tasks without taking into account their goals has no methodological merit. Task analysis should therefore be defined as the study of what a person or a team is required to do to achieve a specific goal or, simply put, as who does what and why. The contents of the task are usually described in terms of the actions and/or cognitive processes involved. The goal describes the purpose of the task as, a specific system state or condition that is to be achieved. A goal may, however, also be a psychological state or objective, such as “having done a good job” The task analysis literature has usually eschewed the subjective and affective aspects of tasks and goals, although they clearly are essential both for understanding human performance and for designing artefacts and work environments.