Protocol Analysis as a Tool in Function and Task Analysis

A protocol is a record of procedural steps undertaken in a process. In studying human- machine systems, observations of human operators obtained from sources such as videotapes are coded to create a descriptive protocol of behaviours, task elements, goals, etc. This record is essentially sequential in nature, but methods for analysing sequential data are relatively new. The kinds of information that protocol analysis can provide, that might be useful in function/task analysis, are examined. Methods for analysing sequences are surveyed, and recent developments in using minimum message length methods for producing probabilistic finite state automaton models of sequential behaviour are discussed.