Graphical user interfaces validation: a problem analysis and a strategy to solution

This paper begins by justifying the importance of graphical user interfaces (GUIs) and the need for proper validation. The various problems in GUI validation are classified into 3 categories : functional, structural and environmental issues. The functional aspects of GUI are examined from the mapping of display objects on screen, interaction functions, to basic interaction components and window management functions. The largest functional issue identified is the lack of a formal specification suitable for deriving test cases. The main structural problem is in deciding on which of the software levels (i.e. window systems, toolkits, UIMS and applications) to target tests. The environmental issues concern human testers, automation, input synthesis and output visual verification. At the heart of all software testing activities, whether GUI or conventional, lies the problem of test case selection as testing budgets are finite. This paper concludes with a strategy for validation, based on derivation of test cases from a formal specification