Specifying collaborative software: a proposal

The aim of this paper is to illustrate how formal specifications for collaborative interactive systems might be written. It presents a new modelling paradigm for certain systems. It also shows how formal software engineering approaches can be useful. Specifically we choose to specify a simple collaborative editor. This example serves two purposes: it shows how clear and simple a formal specification can be and it provides a basis for making observations about the requirements for a specification language where the target is CSCW systems. The specification of the system has three parts: the semantics of the system; the syntax of the system; the semantics of the collaborative aspects of the system

Frameworks for enhancing temporal interface behaviour through software architectural design

The work reported in this thesis is concerned with understanding aspects of temporal behaviour. A large part of the thesis is based on analytical studies of temporal properties and interface and architectural concerns. The main areas covered include: i. analysing long-term human processes and the impact of interruptions and delays ii. investigating how infrastructures can be designed to support synchronous fast pace activity iii.design of the Getting-to-Know (GtK) experimental notification server The work is motivated by the failure of many collaborative systems to effectively manage the temporal behaviour at the interface level, as they often assume that the interaction is taking place over fast, reliable local area networks. However, the Web has challenged this assumption and users are faced with frequent network-related delays. The nature of cooperative work increases the importance of timing issues. Collaborative users require both rapid feedback of their own actions and timely feedthrough of other actions. Although it may appear that software architectures are about the internals of system design and not a necessary concern for the user interface, internal details do show up at the surface in non-functional aspects, such as timing. The focus of this work is on understanding the behavioural aspects and how they are influenced by the infrastructure. The thesis has contributed to several areas of research: (a)the study of long-term work processes generated a trigger analysis technique for task decomposition in HCI (b)the analysis of architectures was later applied to investigate architectural options for mobile interfaces (c)the framework for notification servers commenced a design vocabulary in CSCW for the implementation of notification services, with the aim of improving design (d)the impedance matching framework facilitate both goal-directed feedthrough and awareness In particular, (c) and (d) have been exercised in the development of the GtK separable notification server