Uncovering Dependence Clusters and Linchpin Functions

Dependence clusters are (maximal) collections of mutually dependent source code entities according to some dependence relation. Their presence in software complicates many maintenance activities including testing, refactoring, and feature extraction. Despite several studies finding them common in production code, their formation, identification, and overall structure are not well understood, partly because of challenges in approximating true dependences between program entities. Previous research has considered two approximate dependence relations: a fine-grained statement-level relation using control and data dependences from a program’s System Dependence Graph and a coarser relation based on function-level controlflow reachability. In principal, the first is more expensive and more precise than the second. Using a collection of twenty programs, we present an empirical investigation of the clusters identified by these two approaches. In support of the analysis, we consider hybrid cluster types that works at the coarser function-level but is based on the higher-precision statement-level dependences. The three types of clusters are compared based on their slice sets using two clustering metrics. We also perform extensive analysis of the programs to identify linchpin functions – functions primarily responsible for holding a cluster together. Results include evidence that the less expensive, coarser approaches can often be used as e�ective proxies for the more expensive, finer-grained approaches. Finally, the linchpin analysis shows that linchpin functions can be e�ectively and automatically identified.

Professional development for professional learners: teachers’ experiences in Norway, Germany and England

Proposals made by the European Commission in 2007 led to the Education Council adopting, for the first time, a European agenda for improving the quality of teaching and teacher education. This article reports on a small-scale longitudinal interview-based study with teachers in England, Norway and Germany demonstrating that while opportunities for professional development are increasing in all three countries, dissatisfaction is expressed by most teachers in relation to its quality and outcomes.

Civil defence pedagogies and narratives of democracy: disaster education in Germany

‘Disaster education’ is a fledgling area of study in lifelong education. Many countries educate their populations for disasters, to mitigate potential damage and loss of life, as well as contribute to national security. In this paper, which draws on interview data from the German Federal Office for Civil Defence and Disaster Assistance and the Federal Agency for Technical Relief, archival research, analysis of websites and promotional materials as well as relevant academic literature, I examine disaster education and preparedness for national emergencies in Germany. I argue that it is not generally extended to the general public, rather confined to trained experts, decentralised, localised and exclusive. Theorising disaster education as a ‘civil defence pedagogy’ (Preston, 2008), a type of public pedagogy, which contributes to shaping narratives of national identity, I argue that it is unlikely that Germany will develop a more inclusive, universal, formalised, nor high-profile campaign in disaster education in the foreseeable future. This, I suggest, is due to narratives of the German democratic nation state as secure, federal, peaceful and unified, which originated at the founding of West Germany in 1949, and continue to shape contemporary political narratives.