New graphical and text-based notations for representing task decomposition hierarchies: towards improving the usability of an Ergonomics method

摘要

The representation of task decompositions, in the form of sub-goalrnhierarchies and their related sequencing triggering and exitrnconditions, lies at the heart of hierarchical task analysis (HTA) andrnrelated techniques. Analysis of the conventional graphical and textbasedrnnotations for these representations, using the principlesrnof cognitive load theory, identifies a number of features that mayrngive rise to difficulties when reading and constructing HTArnrepresentations. A revised graphical notation is presented, derivedrnfrom similar notations that are used in the software engineering andrnhuman factors domains. An equivalent text-based notation is alsornpresented to facilitate the representation of the task decompositionrntabular format, where additional details of the task can be captured.rnIt is suggested that the use of these revised notations could improvernusability when constructing and interpreting graphical and tabularrnrepresentations of hierarchical task decompositions.