Theses and Dissertations from UMD
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New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM
More information is available at Theses and Dissertations at University of Maryland Libraries.
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Item Feedback-Directed Model-Based GUI Test Case Generation(2008-08-15) Yuan, Xun; Memon, Atif M; Computer Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Most of today's software users interact with the software through a graphical user interfac (GUI), which is a representative of the broader class of event-driven software (EDS). As the correctness of the GUI is necessary to ensure the correctness of the overall software, its quality assurance (QA) is becoming increasingly important. During software testing, an important QA technique, test cases are created and executed on the software. For GUIs, test cases are modeled as sequences of user input events. Because each possible sequence of user events may potentially be a test case and because today's GUIs offer enormous flexibility to end users, in principle, GUI testing requires a prohibitively large number of test cases. Any practical test case generation technique must sample the vast GUI input space. Existing techniques are either extremely resource intensive or do not adequately model complex GUI behaviors, thereby limiting fault detection. This research develops new models, algorithms, and metrics for automated GUI test case generation. A novel aspect of this work is its use of software runtime information collected as feedback during GUI test case execution, and used to generate additional test cases that model complex GUI behaviors. One set of empirical studies show that the feedback directed technique significantly improves upon existing techniques and helps to identify serious problems in fielded GUIs. Another set of studies conducted on in-house software applications show that the test suites generated by the new technique outperform their coverage equivalent counterparts in terms of fault detection. Although the focus of this work is on the GUI domain, the techniques developed are general and are applicable to the broader class of EDS. In fact, this work has already had an impact on research and practice of testing other EDS. In particular, the work has been extended by other researchers to test web applications.Item Developing Cost-Effective Model-Based Techniques for GUI Testing(2006-08-28) Xie, Qing; Memon, Atif; Computer Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Most of today's software users interact with the software through a graphical user interface (GUI), which constitutes as much as 45-60% of the total code. The correctness of the GUI is necessary to ensure the correctness of the overall software. Although GUIs have become ubiquitous, testing GUIs for functional correctness has remained a neglected research area. Existing GUI testing techniques are extremely resource intensive primarily because GUIs have very large input spaces and evolve frequently. This dissertation overcomes the limitations of existing techniques by developing a process with supporting models, techniques, and tools for continuous integration testing of evolving GUI-based applications. The key idea of this process is to create three concentric testing loops, each with specific GUI testing goals, resource usage, and targeted feedback. The innermost fully automatic loop called crash testing operates on each code change of the GUI software. The second semi-automated loop called smoke testing operates on each day's GUI build. The outermost loop called comprehensive GUI testing is executed after a major version of the GUI is available. The primary enablers of this process, also developed in this dissertation, include an abstract model of the GUI and a set of model-based techniques for test-case generation, test oracle creation, and continuous GUI testing. The model and techniques were obtained by studying GUI faults, interactions between GUI events, and why certain event interactions lead to faults. The continuous testing process and associated techniques are shown to be useful, via several large experiments involving millions of test cases, on both in-house and open-source GUI applications.Item DOMAIN SPECIFIC TEST CASE GENERATION USING HIGHER ORDERED TYPED LANGUAGES FOR SPECIFICATION(2005-04-14) Sinha, Avik; Smidts, Carol S; Reliability Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Model based testing is an approach for automatic generation of test cases on the basis of a representative model of the system. Recent studies show that model based testing has many possible advantages over manual test generation techniques including a gain in effectiveness, efficiency and reuse. The effectiveness (ability to uncover faults in a system) of a model based testing process is determined by the correctness of the model and by the number of requirements represented in the model. In practice, test models for model based test automation techniques are usually created from requirement or design specifications of the software and hence, these techniques overtly rely on such specifications for the completeness of the test models. This may lead to failure in testing some critical requirements specific to the application domain because the user, who helps in defining the requirements, may fail to consider certain domain specific requirements. To him some may appear to be too trivial to be specified explicitly in the requirements document and the others, he may forget. Even if the requirement is complete with domain specific requirements, testers may not realize criticality of such requirements or may find them too complex to model. In all such cases, testing is incomplete and ineffective. This dissertation describes a new model based testing technique developed to remedy such situations. The new technique is based on modeling the system under test using a strongly typed domain specific language (DSL). In the new technique, information about domain specific requirements of an application are captured automatically by exploiting properties of the DSL and are subsequently introduced in the test model. The new technique is applied to generate test cases for the applications interfacing with relational databases and the example DSL chosen for that purpose is HaskellDB. Test suites generated using the new technique are enriched with test cases addressing domain specific implicit requirements and therefore, are more effective in finding faults. This dissertation will present details of the technique and describe an experiment and a case study to explore its effectiveness, efficiency, usability and industrial applicability.