Andrew Deacon

Merging application-centric and data-centric approaches to support transaction-oriented multi-system workflows

Workflow management is primarily concerned with dependencies between the tasks of a workflow, to ensure correct control flow and data flow. Transaction management, on the other hand, is concerned with preserving data dependencies by preventing execution of conflicting operations from multiple, concurrently executing tasks or transactions. In this paper we argue that many applications will be served better if the properties of transaction and workflow models are supported by an integrated architecture. We also present preliminary ideas towards such an architecture.

Learning as acquiring a discursive identity through participation in a community: improving student learning in engineering education

In this paper, we propose that learning in engineering involves taking on the discourse of an engineering community, which is intimately bound up with the identity of being a member of that community. This leads to the notion of discursive identity, which emphasises that students’ identities are constituted through engaging in discourse. This view of learning implies that success in engineering studies needs to be defined with particular reference to the sorts of identities that students develop and how these relate to identities in the world of work. In order to achieve successful learning in engineering, we need to recognise the multiple identities held by our students, provide an authentic range of engineering-related activities through which students can develop engineering identities and make more explicit key aspects of the discourse of engineering of which lecturers are tacitly aware. We include three vignettes to illustrate how some of the authors of this paper (from across three different institutions) have applied this perspective of learning in their teaching practice.

Semantics-based multilevel transaction management in federated systems

A federated database management system (FDBMS) is a special type of distributed database system that enables existing local databases, in a heterogeneous environment, to maintain a high degree of autonomy. One of the key problems in this setting is the coexistence of local transactions and global transactions, where the latter access and manipulate data of multiple local databases. In modeling FDBMS transaction executions the authors propose a more realistic model than the traditional read/write model; in their model a local database exports high-level operations which are the only operations distributed global transactions can execute to access data in the shared local databases. Such restrictions are not unusual in practice as, for example, no airline or bank would ever permit foreign users to execute ad hoc queries against their databases for fear of compromising autonomy. The proposed architecture can be elegantly modeled using the multilevel nested transaction model for which a sound theoretical foundation exists to prove concurrent executions correct. A multilevel scheduler that is able to exploit the semantics of exported operations can significantly increase concurrency by ignoring pseudo conflicts. A practical scheduling mechanism for FDBMSs is described that offers the potential for greater performance and more flexibility than previous approaches based on the read/write model.<<ETX>>

Learning through engagement: MOOCs as an emergent form of provision

Abstract Massive open online courses (MOOCs) are a new form of educational provision occupying a space between formal online courses and informal learning. Adopting measures used with formal online courses to assess the outcomes of MOOCs is often not informative because the context is very different. The particular affordances of MOOCs shaping learning environments comprise scale (in terms of numbers of students) and diversity (in terms of the types of students). As learning designers, we focus on understanding the particular tools and pedagogical affordances of the MOOC platform to support learner engagement. Drawing on research into learner engagement conducted in the broader field of online learning, we consider how learner engagement in a MOOC might be designed for by looking at three pedagogical aspects: teacher presence, social learning, and peer learning.

MOOC—making and open educational practices

MOOCs have been seen as holding promise for advancing Open Education. While the pedagogical design of the first MOOCs grew out of the Open Education Movement, the current trend has MOOCs exhibiting fewer of the original openness goals than anticipated. The aim of this study is to examine the practices and attitudes of MOOC educators at an African university and ask whether and how their practices and attitudes become open after creating and teaching a MOOC. Activity Theory is used to contextually locate the educators’ motivations and to analyse their practices in terms of striving towards an object. With this lens we describe how educators’ openness-related practices and attitudes change over time in two different MOOCs. Two sets of conceptions of open practices are used to detect instances of change, providing four dimensions of changed open educational practices. Semi-structured interviews, focus groups, and artefacts provide data for this rare study, which considers these issues from the perspective of the Global South. Through studying the educators’ practices in relation to openness, it becomes evident how open practices are emergent and responsive.

Media Rich, Resource Poor: Practical Work in an Impractical Environment.

Film and media courses appear well placed to exploit technology convergence in exposing students both to practical skills and to theoretical concepts. For the University of Cape Towns (UCT) large film and media studies courses, it is impractical simply to use the technology of professionals as this would typically be too expensive to purchase and time-consuming to run. Our approach has been to develop activities that can run with large classes in generic computer laboratories and which simulate environments and tools of the real world. Two illustrative examples, emphasising writing skills in context, involve the production of a TV news story and the development of a proposal for an educational soap opera. Using these, we reflect on our experience of integrating practical skills into the curriculum of a traditional academic institution, where these skills have a lower status and must be sufficiently flexible to accommodate changes in the higher-status academic components. This suggests that such flexibility has to be part of the design of practical interventions and that they should additionally aim to provide a challenge to some of the more theoretical aspects of these courses. While developing ones own interventions allows for some of this flexibility to be incorporated into the design, it remains difficult for academic departments to adopt these solutions as their own, thus requiring continued involvement of the original developers to adapt to changes.

A study of graduate students in an astrophysics bridging year: Identifying contradictions in a complex system

Black South African students who transfer from “Historically Black Universities” to the National Graduate Program in Astrophysics and Space Science at the University of Cape Town often struggle academically. While our previous studies focused on student epistemology and went some way towards understanding student under-performance it became clear that broader socio-cultural and systemic issues were playing critical roles. Using Cultural Historical Activity Theory (CHAT) as a theoretical perspective we (a) characterized the broader context as an Activity System and (b) identified the four main types of systemic contradictions as proposed by the theory.