| This dissertation describes the research we performed studying three different ad hoc query interfaces to databases. We wanted to determine which of the interfaces was easiest to learn and which one allowed subjects to be most productive. The interfaces we used were all commercial query languages and they were chosen to represent three different interface models: for an artificial language (i.e., formal computer language) interface we used SQL, for a graphical language interface we used Simplify, and for natural language interface, (i.e., English) we used DataTalker.; Subjects were used taught how to use one of the three interfaces during a learning phase of the experiment, and they were tested on that interface during a performance phase. The subjects ranged in ability from no computer experience at all to experts on each of the interfaces studied. They were tested over a range of tasks from simple single table queries through complex joins.; We analyzed the quantitative results of the performance of the subjects in terms of their ability to complete the tasks and in terms of their ability of complete the tasks and in terms of the time they needed to complete the successful tasks. We also studied the qualitative data drawn from observations we made of the subjects during the experiment and comments made by the subjects both during and after the experiment.; The results showed that though no interface was uniformly best, different groups of users did best with each interface. Expert users on each interface and subjects who had not used computers before did best when using SQL, users familiar with SQL and programmers did best when using Simplify, and computer users without programming experience did best when using DataTalker. We conclude that the graphical and natural language interfaces show promise as a better interface overall than the artificial language. Today, however, an artificial language still has the best general applicability. ftn*Research supported in part by a grant from BP America and the National Science Foundation under grant MIP 87-15557. |
