Will My Tests Tell Me If I Break This Code?

Automated tests play an important role in software evolution because they can rapidly detect faults introduced during changes. In practice, code-coverage metrics are often used as criteria to evaluate the effectiveness of test suites with focus on regression faults. However, code coverage only expresses which portion of a system has been executed by tests, but not how effective the tests actually are in detecting regression faults. Our goal was to evaluate the validity of code coverage as a measure for test effectiveness. To do so, we conducted an empirical study in which we applied an extreme mutation testing approach to analyze the tests of open-source projects written in Java. We assessed the ratio of pseudo-tested methods (those tested in a way such that faults would not be detected) to all covered methods and judged their impact on the software project. The results show that the ratio of pseudo-tested methods is acceptable for unit tests but not for system tests (that execute large portions of the whole system). Therefore, we conclude that the coverage metric is only a valid effectiveness indicator for unit tests.Comment: 7 pages, 3 figure

A frequency-selective feedback model of auditory efferent suppression and its implications for the recognition of speech in noise

The potential contribution of the peripheral auditory efferent system to our understanding of speech in a background of competing noise was studied using a computer model of the auditory periphery and assessed using an automatic speech recognition system. A previous study had shown that a fixed efferent attenuation applied to all channels of a multi-channel model could improve the recognition of connected digit triplets in noise [G. J. Brown, R. T. Ferry, and R. Meddis, J. Acoust. Soc. Am. 127, 943?954 (2010)]. In the current study an anatomically justified feedback loop was used to automatically regulate separate attenuation values for each auditory channel. This arrangement resulted in a further enhancement of speech recognition over fixed-attenuation conditions. Comparisons between multi-talker babble and pink noise interference conditions suggest that the benefit originates from the model?s ability to modify the amount of suppression in each channel separately according to the spectral shape of the interfering sounds

Do Heterogeneous Beliefs Matter for Asset Pricing?

We study how heterogeneous beliefs affect returns and examine whether heterogeneous beliefs are a priced factor in traditional asset pricing models. To accomplish this task, we suggest new empirical measures based on the disagreement among analysts about expected (short-term and long-term) earnings are good proxies. Having established that heterogeneity of beliefs matters for asset pricing we turn our attention to estimating a structural model in which we use the forecasts of financial analysts to proxy for the beliefs of agents. Finally, we investigate if the amount of heterogeneity in analysts' forecasts can help explain asset pricing puzzlesHeterogeneous Beliefs, Asset pricing

U.N. Women\u27s Event Unleashed Powerful Ideas

Juergens describes her experience at the Non-Governmental Organizations Forum of the United Nations\u27 Fourth World Conference on Women, where a Platform for Action , the U.N. action plan for women and girls was created

Rosalie Wahl\u27s Vision for Legal Education: Clinics at the Heart

Rosalie Wahl holds a special place in the hearts of Minnesota lawyers. Many women and girls, especially, were gratified when Governor Rudy Perpich appointed her the first woman on the Minnesota Supreme Court in 1977. There were no more than nine other women on supreme courts around the country at the time, and none on the U.S. Supreme Court. She served on the court until 1994, when the law mandating judges’ retirement at age seventy caused her to step down from the bench. This essay highlights the significance of Wahl’s work as a clinical legal educator and activist for legal education. It begins with a brief account of Wahl’s growth into her work as a lawyer. The article then focuses on her time as a clinical law teacher and, later, as a leader in the ABA Section of Legal Education and Admissions to the Bar. It closes with thoughts about what Wahl’s example means for law teachers

Valuing Small Firm and Solo Law Practice: Models for Expanding Service to Middle-Income Clients

While the profession focuses on ways to meet the critical legal needs of low-income citizens, the needs of the middle group are largely left for the market to fill. The painful fact is that the market has failed to distribute lawyer services to a majority of Americans with legal needs. Ironically, the legal needs of middle-income Americans have risen with the economic crisis even as unemployment among new lawyers has increased. A large supply of trained lawyers without work theoretically should translate into lower costs and more legal needs being met. Yet the cost of legal services has continued to rise. Great unmet need coupled with high cost of services and numerous underemployed new lawyers are allied problems that the profession can ill afford to avoid. The challenge is to use this tempest to rethink the profession’s approach to solving legal problems, lowering the cost of service, and expanding the distribution of justice. This article assumes that it is a legitimate goal of the profession to increase access to civil justice facilitated by lawyers - as contrasted with access facilitated by self or paralegals or document assemblers - and that the profession must chart alternatives beyond pro bono, legal aid and pro se justice for clients. That project is the focus of this article