ORBS and the limits of static slicing

Observation-based slicing is a recently-introduced, language-independent, slicing technique based on the dependencies observable from program behaviour. Due to the wellknown limits of dynamic analysis, we may only compute an under-approximation of the true observation-based slice. However, because the observation-based slice captures all possible dependence that can be observed, even such approximations can yield insight into the limitations of static slicing. For example, a static slice, S that is strictly smaller than the corresponding observation based slice is guaranteed to be unsafe. We present the results of three sets of experiments on 12 different programs, including benchmarks and larger programs, which investigate the relationship between static and observation-based slicing. We show that, in extreme cases, observation-based slices can find the true static minimal slice, where static techniques cannot. For more typical cases, our results illustrate the potential for observation-based slicing to highlight unsafe static slices. Finally, we report on the sensitivity of observation-based slicing to test quality.

Flourishing as a dialectical balance: emerging insights from second-wave positive psychology

Positive psychology, an emergent branch of scholarship concerned with wellbeing and flourishing, initially defined itself by a focus on “positive” emotions and qualities. However, critics soon pointed out that this binary logic—classifying phenomena as either positive or negative, and valorising the former while disparaging the latter—could be problematic. For example, apparently positive qualities can be harmful to wellbeing in certain circumstances, while ostensibly dysphoric emotional states may on occasion promote flourishing. Responding to these criticisms, over recent years a more nuanced “second wave” of positive psychology has been developing, in which wellbeing is recognized as involving a dialectical balance of light and dark aspects of life. This article introduces this emergent second wave, arguing that it is characterized by four dialectical principles. First, the principle of appraisal states that it is difficult to categorically identify phenomena as either positive or negative, since such appraisals are fundamentally contextually dependent. Second, the principle of co-valence holds that many states and qualities at the heart of flourishing, such as love, are actually a complex blend of light and dark elements. Third, the principle of complementarity posits that not only are such phenomena co-valenced, but that their dichotomous elements are in fact co-creating, two intertwined sides of the same coin. Finally, the principle of evolution allows us to understand second-wave positive psychology as itself being an example of a dialectical process. This article is published as part of a collection entitled “On balance: lifestyle, mental health and wellbeing”.