Hierarchical task analysis vs. cognitive work analysis: comparison of theory, methodology and contribution to system design

Abstract

The cognitive work analysis framework continues to attract increasing attention from the human factors and ergonomics community. Conversely, hierarchical task analysis has been, and remains, the most popular of all human factors and ergonomics methods. This article compares the two approaches in terms of their theoretical underpinning, methodological approach and potential contributions to system design and evaluation. To do this, recent analyses, involving both approaches, of a military rotary wing mission planning software tool are compared and contrasted in terms of their methodological procedure and analysis outputs. The findings indicate that, despite the very different theoretical and methodological nature of the two approaches, and also the entirely different analyses derived, the two methods provide highly complementary outputs. In conclusion, it is argued that there is benefit in applying both approaches to inform the design and/or evaluation of the same product or system.

Keywords:

• cognitive work analysis
• hierarchical task analysis
• mission planning
• human factors methods

Acknowledgements

This work from the Human Factors Integration Defence Technology Centre was part-funded by the Human Sciences Domain of the UK Ministry of Defence Scientific Research Programme. The authors would like to thank Nick Wharmby, Shaun Wyatt, Jan Ferraro and Sean Dufosee for their assistance in the data collection, data analysis and interpretation of the analysis products. Also, the authors would like to thank the anonymous reviewers whose comments helped to improve this article significantly.