Work domain analysis

The initial phase within the Cognitive work analysis (CWA) framework, Work Domain Analysis, provides a description of the constraints that govern the purpose and the function of the systems under analysis. The Abstraction Hierarchy (Rasmussen, 1985; Vicente, 1999) is used to provide a context-independent description of the domain. The analyses, and resultant diagrams, are not specific to any particular technology; rather they represent the entire domain. The top-three levels of the diagrams consider the overall objectives of the domain, and what it can achieve, whereas, the bottom-two levels concentrate on the physical components and their affordances. Through a series of ‘means-ends’ links, it is possible to model how individual components can affect the overall domain purpose. The abstraction hierarchy is constructed by considering the work system’s objectives (top-down) and the work system’s capabilities (bottom-up). The diagram is constructed based upon a range of data collection opportunities. The exact data collection procedure is dependent on the domain in question and the availability of data. In most cases, the procedure commences with some form of document analysis. Document analysis allows the analyst to gain a basic domain understanding, forming the basis for semi-structured interviews with domain experts. Wherever possible, observation of the work in context is highly recommended. The initial phase within the Cognitive work analysis (CWA) framework, Work Domain Analysis, provides a description of the constraints that govern the purpose and the function of the systems under analysis. The Abstraction Hierarchy (Rasmussen, 1985; Vicente, 1999) is used to provide a context-independent description of the domain. The analyses, and resultant diagrams, are not specific to any particular technology; rather they represent the entire domain. The top-three levels of the diagrams consider the overall objectives of the domain, and what it can achieve, whereas, the bottom-two levels concentrate on the physical components and their affordances. Through a series of ‘means-ends’ links, it is possible to model how individual components can affect the overall domain purpose. The abstraction hierarchy is constructed by considering the work system’s objectives (top-down) and the work system’s capabilities (bottom-up). The diagram is constructed based upon a range of data collection opportunities. The exact data collection procedure is dependent on the domain in question and the availability of data. In most cases, the procedure commences with some form of document analysis. Document analysis allows the analyst to gain a basic domain understanding, forming the basis for semi-structured interviews with domain experts. Wherever possible, observation of the work in context is highly recommended. The abstraction hierarchy consists of five levels of abstraction, ranging from the most abstract level of purposes to the most concrete level of form (Vicente, 1999). The labels used for each of the levels of the hierarchy tend to differ, dependent on the aims of the analysis. In this case, the labels used by Xiao et al are adopted. It is felt that the use of the word ‘domain’ in the top three levels and the use of the word ‘physical’ in the bottom two levels draws a fitting distinction.