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 available (e.g., a mouse and button) as well as by the ways in which elementary cognitive, perceptual, and motor operations can be combined. Any 2 basic activities, for example, (a) moving to and (b) clicking on a button, can be combined to yield a limited number of microstrategies. The results of an experimental 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) bracketing the range of individual performance, (b) profiling individual differences, and (c) diagnosing mismatches between expected and obtained performance. These 2 studies support the arguments that the microstrategies deployed can be sensitive to small features of an interface and that task analyses at the millisecond level can inform design.

Effects of different data base formats on information retrieval.

This research examined the effects of three different data base formats on the information retrieval performance of users. Spatial, tabular, and verbal forms of two data base domains (airline and thesaurus) were constructed, along with questions that required users to search through the data base to determine the correct response. Three types of questions, compatible with the forms of the data bases, were designed--spatial, tabular, and verbal. The data indicate that users' responses to the questions are faster and more accurate when the format of the information in the data base matches the type of information needed to answer the question. Although the importance of matching data base format to query type may seem obvious, it would appear that the designers of most current data base systems have not taken this into account.