Optimization of a human interface to access image data bases

The authors describe an experimental evaluation of the usability of a user interface for accessing image databases by means of relational queries. After evaluating the performance of an earlier version of the interface, a human factors study was carried out to improve its friendliness. Then a second usability test was performed and the results were compared with those of the previous one. Both naive and experienced users took part in the experiments. They had to solve three tasks which consisted of retrieving a given image from the database. The following data were collected automatically: performance time and error rate as a function of the number of trials and the experience level, and subjective reactions to the use of the interface. The results show that the second version of the interface is characterized by better performance times and error rates. Moreover, the gap between the performances of experienced and naive users was reduced. Attitude assessments show that the second version reported better scores as regards ease-of-use, usability, and satisfaction