From sufficient to efficient usage: An analysis of strategic knowledge

Can good design guarantee the efficient use of computer tools? Can experience guarantee it? We raise these questions to explore why empirical studies of real-world usage show even experienced users under-utilizing the capabilities of computer applications. By analyzing the use of everyday devices and computer applications, as well as reviewing empirical studies, we conclude that neither good design nor experience may be able to guarantee efficient usage. Efficient use requires task decomposition strategies that exploit capabilities offered by computer applications such as the ability to aggregate objects, and to manipulate the aggregates with powerful operators. To understand the effects that strategies can have on performance, we present results from a GOMS analysis of a CAD task. Furthermore, we identify some key aggregation strategies that appear to generalize across applications. Such strategies may provide a framework to enable users to move from a sufficient to a more efficient use of computer tools.