Milliseconds matter: An introduction to microstrategies and to their use in describing and predicting interactive behavior

interactive behavior is constrained by the design of the artifacts availabl e (e.g., a mouse and button) as well as by the ways in which elementary cog nitive, perceptual, and motor operations can be combined. Any 2 basic activ ities, for example, (a) moving to and (b) clicking on a button, can be comb ined to yield a limited number of microstrategies. The results of an experi mental study suggest that alternative microstrategies can be deployed that shave milliseconds from routine interactive behavior. Data from a usability study are used to explore the potential of microstrategies for (a) bracket ing the range of individual performance, (b) profiling individual differenc es, and (c) diagnosing mismatches between expected and obtained performance . These 2 studies support the arguments that the microstrategies deployed c an be sensitive to small features of an interface and that task analyses at the millisecond level can inform design.