This work was done in the context of an interdisciplinary project (called ITS) aimed at producing new tools for computer application development. One motivation is to provide designers with a computer-based toolkit from which they can select human-computer interaction techniques appropriate to various contexts and conditions. These experiments extend our work to touchscreens, and provide a basis of comparison with keyboards and arrow keys. Three human- computer interaction methods, including basic entry and autocompletion, were studied in two simple laboratory scenarios: participants specified dates and airlines reservations. Autocompletion was preferred over, and was faster than, basic entry. The a priori countable, minimum number of touches required to use a particular interaction method is a good predictor of how much time people will need to use that interaction method on a particular task. Similar results were found previously with keyboards and arrow keys. © 1990 Oxford University Press.