1. HTA as a framework for task analysis a review by Andrew Wright (2.8.16)

2. Article Details HTA as a framework for task analysis A. SHEPHERD Department of Human Sciences, Loughborough University, Loughborough LE11 3TU, UK Keywords: Task analysis; Cognitive task analysis; Complex tasks.

3. Main features of the article Quite strongly in favor of Hierarchical Task Analysis (HTA) Explores scenarios in which HTA could (should?) be more correctly used Looks at pros and cons of “toolkit” type approaches to TA Examines the role of Cognitive Task Analysis (CTA) within this approach

4. Approach of the article “This paper will adopt the perspective of a `task’ as a problem facing an operator, with task analysis serving to identify strategies by which the operator can be facilitated to solve the problem, by information design, task re- organization, training and any other human factor.”

5. Why HTA? HTA aligned with systems theory and associated psychology A more complicated system or problems is most suited to HTA Types of hierarchy: authoritarian, delegatory vs descriptive Detail in HTA is dictated less by considerations of behavior than by consideration of criticality in terms of the system under scrutiny.

6. Figure 1. The Hierarchical Task Analysis framework

7. The HTA framework Box 1: Setting goals Box 2: Observing constraints: Box 3: Calculating criticality Box 4: Ceasing redescription Box 5: Generating hypotheses: Box 6: Cost-benefit analysis:

8. The HTA framework (cont) Box 7: Recording the analysis Box 8: Redescription Box 9: Challenging the constraints “Task analysis, it is suggested, is a process of examining the human-task interaction in order to establish methods to ensure an appropriate fit’ to meet system requirements, or to identify reasons why there is not an appropriate fit in a given operational configuration.

9. Task analysis & Cognition (1) HTA is concerned with the steps of a task CTA is concerned with capturing a representation of the knowledge of the operator, which may or may not be important Cognitive elements, e.g a decision making process can only be inferred Cognitive processes only evident by changes in action

10. Task analysis & Cognition (2) Cognitive skills for each task must be examined in context E.g. operating a train: supervisor vs. signaling assistant perform the same task but with different considerations Also applies to same person, same task, different variables

11. Conclusion 1.HTA is a framework for analyzing tasks not modeling behavior 2. Cognitive elements exist within the greater task, and can be treated as a subset of HTA