Testing native speakers of German and Portuguese on the understanding of topological operators-line-region relations in gvSIG

Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial Technologies

Usability testing is an essential part of software development, which provides guidelines to the developers according to the users’ needs. In the present usability study, natural language terms that describe topological operators in gvSIG software were tested among native speakers of German and Portuguese. The main goal was find out if users’ understand the operators according to the system designer. Twenty six subjects in each language had to choose the line-regions relations appropriate for each topological operator in gvSIG. Afterwards, the subjects’ answers were compared to the implementation of these topological operators by the gvSIG software. The comparison revealed major difference between the subjects’ answers and the gvSIG implementation. The subjects chose applicable line-region relations out of a set of 19 different topological relations identified by Egenhofer’s 9-intersection model. In average 12% and 6% of the operators were understood in the same way as gvSIG implementation by the subjects of German and Portuguese respectively. For German native speakers, the highest results of an operator understood by the subjects as the system designer were 50% and a subject understanding 33% of the operators. The lowest results of an operator understood by the subjects as the system designer were 0% and a subject understanding 0% of the operators. For Portuguese native speakers, the highest results of an operator understood by the subjects as the system designer were 27% and a subject understanding 33% of the operators. The lowest results of operator understood by subjects as system designer were 0% and a subject understanding 0% of the operators.