Naturalness of Graphical Queries Based on the Entity Relationship Model

Many graphical query languages have been proposed for database access, especially by novice or end-users. One of the major assumptions is that these are natural for them. An empirical study was conducted to measure the naturalness of graphical queries for the entity relationship model. Two aspects of naturalness are assessed. These are the ability to specify graphical queries without being taught and restricted to any particular syntax, and the ability to comprehend graphical queries without being taught the syntax for the graphical system. Graphical queries involving fourteen different query concepts were used in a study with 27 subjects. The results show that well-designed graphical queries can be comprehended without teaching. Not so well designed queries are difficult to comprehend. The natural ability to specify graphical queries is not as good. The results identify clearly those concepts that are naturally easy to specify, and those that are difficult. The findings can be used for designing graphical interfaces, as well as for designing training packages.