Extending conceptual models for Web based applications

The next phase envisioned for the World Wide Web is automated ad-hoc interaction between intelligent agents, web services, databases and semantic web enabled applications. Although at present this appears to be a distant objective, there are practical steps that can be taken to advance the vision. We propose an extension to classical conceptual models to allow the definition of application components in terms of public standards and explicit semantics, thus building into web-based applications, the foundation for shared understanding and interoperability. The use of external definitions and the need to store outsourced type information internally, brings to light the issue of object identity in a global environment, where object instances may be identified by multiple externally controlled identification schemes. We illustrate how traditional conceptual models may be augmented to recognise and deal with multiple identities.

Public Health Psychology: A Conceptual and Practical Framework

Introduction For many years concern for public health has transcended the boundaries of the medical sciences and epidemiology. For the last 50 years or so psychologists have been increasingly active in this field. Recently, psychologists have not only begun to see the need to take action to mould health promoting behaviours in individuals, but have also pointed out the need to join in an effort to develop appropriate social, political, economic and institutional conditions which would help to improve the state of public health. Psychologists have postulated the need to distinguish a new subdiscipline of psychology called public health psychology which, together with other disciplines, would further the realization of this goal. In the following article the historical and international context of health psychology and the changing nature of public health are put forward as having important implications for the establishment of a ‘public health psychology’. These implications are addressed in later sections of the article through the description of conceptual and practical framework of public health psychology in which theory, methods and practice are considered. Many aspects of the conceptual and practical framework of public health psychology have relevance to the health social sciences more generally and forming a basis for interdisciplinary work. The framework of public health psychology, together with the obstacles that need to be overcome, are critically examined within an overall approach that contends it is necessary to increase and improve the contribution of health psychology to public health.

Capabilities : describing what services can do

The ability of agents and services to automatically locate and interact with unknown partners is a goal for both the semantic web and web services. This, \serendipitous interoperability", is hindered by the lack of an explicit means of describing what services (or agents) are able to do, that is, their capabilities. At present, informal descriptions of what services can do are found in \documentation" elements; or they are somehow encoded in operation names and signatures. We show, by ref- erence to existing service examples, how ambiguous and imprecise capa- bility descriptions hamper the attainment of automated interoperability goals in the open, global web environment. In this paper we propose a structured, machine readable description of capabilities, which may help to increase the recall and precision of service discovery mechanisms. Our capability description draws on previous work in capability and process modeling and allows the incorporation of external classi¯cation schemes. The capability description is presented as a conceptual meta model. The model supports conceptual queries and can be used as an extension to the DAML-S Service Pro¯le.