A. N. Badre, T. Catarci, A. Massari, and G. Santucci: Comparative ease of use of a diagrammatic vs. an iconic query language. In Interfaces to Databases. Electronic Series Workshop in Computing, Springer, pages 1-14 (1996).
Few experiments in the database field have validated the influence of visual query systems with respect to accuracy and time scores. The authors carried out a study to compare QBD* and QBI, specifically for the query writing task.
Two groups of sixteen participants were formed based on the results of a background questionnaire. Each group attended to a short training section and then utilized one of the visual query systems to represent six queries. The ANOVA test reported significant differences in the time scores from the following sets of data: all the participants; the participants familiar with databases; and the queries with cycles or at least four entities. The participants who used QBD* spent less time, except when the query contained cycles. Comments from the participants pointed out that the use of AND as a default operator was unclear in QBD*.
The authors concluded that, when more than three entities were involved, QBI performance was affected because the query was not constructed in steps. The effects of cycles in the query for participants working with QBD* was determined to be due to the representation of correspondences between attributes and entities. When an entity occurred multiple times a number was added to the corresponding attribute names. The authors conjecture that the results favor the use of interfaces that offer multiple notations and interaction mechanisms. However, it is not clear how the user will react to a hybrid system because each participant used only one of the visual query systems.