@incollection{strecker_testing,
   author = {Jaymie Strecker and Atif M. Memon},
   title = {Testing Graphical User Interfaces},
   booktitle = {Encyclopedia of Information Science and Technology, Second ed.},
   publisher = {IGI Global},
   year = {2009}
}

In recent years, an emerging trend in software products has been
toward the use of graphical user interfaces (GUIs). More user-friendly
than traditional, text-based interfaces, GUIs serve as the front-end
for a large portion of today's software applications. Technologies
like Ajax are helping to spread familiar GUI interaction styles to Web
applications. With the rise of ubiquitous computing, users are
interacting with GUIs in a widening range of situations—--not just with
their PCs, but with their dishwashers and cars. Critical applications,
such as banking systems, are moving to GUIs as well. Thus, quality
assurance for GUI-based software is growing more important every day.

With GUIs, users enjoy many degrees of freedom in the way they
interact with the software. While this benefits users, it challenges
testers. Because users may interact with a GUI in a variety of
unexpected ways, it is difficult to insure that the software meets its
functional requirements (correctness) and non-functional requirements
(e.g., usability) for all possible interactions. The difficulties are
compounded by the frequent intersection of GUIs with other emerging
technologies, including component-based and service-oriented
architectures. New trends in software development, such as rapid
development cycles, globally distributed developers, and open-source
projects, make the quality assurance process ever more challenging.

This article describes the state of the art in testing GUI-based
software. Traditionally, GUI testing has been performed manually or
semi-manually, with the aid of capture-replay tools. Since this
process may be too slow and ineffective to meet the demands of today's
developers and users, recent research in GUI testing has pushed toward
automation. Model-based approaches are being used to generate and
execute test cases, implement test oracles, and perform regression
testing of GUIs automatically. This article shows how research to date
has addressed the difficulties of testing GUIs in today's rapidly
evolving technological world, and it points to the many challenges
that lie ahead.