A Binary Classifier for Test Case Feasibility Applied to Automatically Generated Tests of Event-Driven Software

Modern software application testing, such as the testing of software driven by graphical user interfaces (GUIs) or leveraging event-driven architectures in general, requires paying careful attention to context. Model-based testing (MBT) approaches first acquire a model of an application, then use the model to construct test cases covering relevant contexts. A major shortcoming of state-of-the-art automated model-based testing is that many test cases proposed by the model are not actually executable. These \textit{infeasible} test cases threaten the integrity of the entire model-based suite, and any coverage of contexts the suite aims to provide. In this research, I develop and evaluate a novel approach for classifying the feasibility of test cases. I identify a set of pertinent features for the classifier, and develop novel methods for extracting these features from the outputs of MBT tools. I use a supervised logistic regression approach to obtain a model of test case feasibility from a randomly selected training suite of test cases. I evaluate this approach with a set of experiments. The outcomes of this investigation are as follows: I confirm that infeasibility is prevalent in MBT, even for test suites designed to cover a relatively small number of unique contexts. I confirm that the frequency of infeasibility varies widely across applications. I develop and train a binary classifier for feasibility with average overall error, false positive, and false negative rates under 5\%. I find that unique event IDs are key features of the feasibility classifier, while model-specific event types are not. I construct three types of features from the event IDs associated with test cases, and evaluate the relative effectiveness of each within the classifier. To support this study, I also develop a number of tools and infrastructure components for scalable execution of automated jobs, which use state-of-the-art container and continuous integration technologies to enable parallel test execution and the persistence of all experimental artifacts.

Aging African American Women and the Impact of Positive Psychological Factors on Quality of Life

Aging African-American women are disproportionately affected by negative health outcomes and mortality. Life stress has strong associations with these health outcomes. The purpose of this research was to understand how aging African American women manage stress. Specifically, the effects of coping, optimism, resilience, and religiousness as it relates to quality of life were examined. This cross-sectional exploratory study used a self-administered questionnaire and examined quality of life in 182 African-American women who were 65 years of age or older living in senior residential centers in Baltimore using convenience sampling. The age range for these women was 65 to 94 years with a mean of 71.8 years (SD = 5.6). The majority (53.1%) of participants completed high school, with 23 percent (N = 42) obtaining college degrees and 19 percent (N = 35) holding advanced degrees. Nearly 58 percent of participants were widowed and 81 percent were retired. In addition to demographics, the questionnaire included the following reliable and valid survey instruments: The Brief Cope Scale (Carver, Scheier, & Weintraub, 1989), Optimism Questionnaire (Scheier, Carver, & Bridges, 1994), Resilience Survey (Wagnild & Young, 1987), Religiousness Assessment (Koenig, 1997), and Quality of Life Questionnaire (Cummins, 1996). Results revealed that the positive psychological factors examined were positively associated with and significant predictors of quality of life. The bivariate correlations indicated that of the six coping dimensions measured in this study, planning (r=.68) was the most positively associated with quality of life. Optimism (r=.33), resilience (=.48), and religiousness (r=.30) were also significantly correlated with quality of life. In the linear regression model, again the coping dimension of planning was the best predictor of quality of life (beta = .75, p <.001). Optimism (beta = .31, p <.001), resilience (beta = .34, p, .001) and religiousness (beta = .17, p <.01) were also significant predictors of quality of life. It appears as if positive psychology plays an important role in improving quality of life among aging African-American women.

FROM THE AETHIOPICA TO THE RENAISSANCE: RECOVERING A STAGE TRADITION OF POSITIVE REPRESENTATION OF AFRICANS IN EARLY MODERN ENGLAND

This dissertation looks at the connection between Heliodorus's fifth-century prose romance, An Aethiopian History, certain Renaissance texts, and how these texts helped influence an alternate representation of Africans in the early modern world. Through their portrayals of Africans, early modern English playwrights frequently give the impression that Africans, especially black Africans, were people without accomplishments, without culture. Previously, however, this was not the case. Africans were depicted with dignity, as a tradition existed for this kind of representation--and Renaissance Europe had long been acquainted with the achievements of Africans, dating back to antiquity. As the source of several lost plays, the Aethiopica is instrumental in dramatizing Africans favorably, especially on the early modern stage, and helped shape a stage tradition that runs alongside the stereotyping of Africans. This Heliodoran tradition can be seen in works of Greene, Heywood, Jonson, Shakespeare, and others in the motifs of crosscultural and transracial romance, male and female chastity, racial metamorphosis, lost or abandoned babies, wandering heroes, and bold heroines. In Jonson's Masque of Blackness and Masque of Beauty, I establish a connection between these two masques and Heliodorus's Aethiopica and argue for a Heliodoran stage tradition implicit in both masques through the conceit of blanching. In The English Moore, I explore how Richard Brome uses the Heliodoran and Jonsonian materials to create a negative quality of blackness that participates in the dramatic tradition of the degenerate African on the English Renaissance stage. With Othello, I contend that it is a drama that can be seen in the Heliodoran tradition by stressing certain motifs found in the play that derives from the Aethiopica. Reading Othello this way provides us with a more layered and historicized interpretation of Shakespeare's protagonists. Othello's nationality and faith make his exalted position in Venice and the Venetian army credible and logical. His nobility and heroic status become more sharply defined, giving us a fuller understanding of the emphasis he places on chastity--both for himself and for Desdemona. Instead of a traditional, compliant, and submissive Desdemona, a courageous, resourceful, witty, and pure heroine emerges--one who lives by the dictates of her conscience than by the constraints of societal norms. Recovering the tradition of positive portrayal of Africans that originated from the Aethiopica necessitated an examination of eleven plays that I contend helped to frame the dramatic tradition under investigation. Six of these plays are continental dramas, and five are English. Although three of the English plays are lost and the other two are seventeenth-century dramas, their titles and names of their protagonists, like those of the six extant continental plays, share the names of Heliodorus's hero and heroine, making an exploration of the continental plays imperative to facilitate their use as paradigms in reconstructing the three lost English plays. These continental dramas show that plays whose titles derive from the Aethiopica itself or reflect the names of its major characters follow Heliodorus's text closely, enabling an investigation of the Heliodoran tradition on the early modern English stage. Recovering the Heliodoran tradition adds to the exploration of racial politics and the understanding of the dramatic tradition that constrained and enabled Renaissance playwrights' representation of race and gender.