Web services have received much attention because of their potential for realizing service oriented architecture (SOA). As the number of Web services increase exponentially, discovering Web services that satisfy user’s specific needs has become a difficult task. In fact, the ability to find relevant Web services has been recognized as a key challenge in the realization of the potential of service oriented architectures. This chapter is organized as follows: In the next section, we discuss related research and various challenges and issues in Web services discovery. Then, we present several types of ontology and user profiles that may be used in the discovery process. Finally, we introduce a system architecture and discuss future trends and conclusions.
Audience Response Systems
ARS comprise hand-held input devices that transmit data to a receiving device connected to a personal computer. Software processes the datum and presents it in a variety of formats to the participants for discussion. Key components of the system are:
Hand-held input devices: A variety of sizes and designs exist, from the credit-card size keypad with basic numeric input (Figure 1) through to systems that include a display screen to provide feedback to the user.
Receiver: Utilizes infrared or other wireless communication media to collect data from the keypads.
Software: Manages collection and processing of data and supports display of the data in a variety of presentational formats. The software may be embedded in other container software such as PowerPoint. The output from the system is usually displayed on a public screen via a data projector (Figure 2).
Credit-card size kepdad (Source: KEEpad Pty Ltd)
Ars In Higher Education
Draper and Brown (2004, p. 20) suggest that “The dream of personal teaching is really about adaptive teaching; where what is done depends on the learner’s current state of understanding.” ARS can provide timely feedback to support this adaptive teaching goal, but Draper and Brown make the point that this can only be achieved through appropriate pedagogic design and action and not through the technology alone. In one-to-one or small group settings the learning facilitator may have a sense of the current state of the learner if the learner feels sufficiently comfortable in revealing it. With large groups in more formal settings the availability of cues to the learning facilitator can be more limited. The immediate feedback that an ARS offers can publicly identify differences or similarities of opinion within groups and provide a trigger for further discussion or analysis of data and re-adjustment of pacing or content. Audience Response Systems can be used with both large (hundreds of participants) and small groups (Banks, 2006) to support lectures, workshops, seminars, and to explore a wide range of subjects. They can be used at undergraduate and postgraduate levels, and within traditional and post-modern paradigms. Subject areas that value discussion, debate, multiple interpretations and direct challenges to accepted wisdom can benefit from this technology, but equally an ARS can be used in subject areas where demonstration of understanding of a fixed body of knowledge is vital. ARS can be used for formative and summative assessment, in the gauging of preliminary level and subsequent stages of understanding of a subject and in the exploration of the concepts that underpin critical issues.
Key Terms in this Chapter
WSDL: An XML-based language used to describe Web services
UDDI: An XML-based registry for businesses to publish and search Web services.
Ontology: A conceptualization of a domain. It is consisted of entities, attributes, relationships and axioms in a format which is human understandable and machine-readable.
Ontology Pruning: A method used to delete the elements of an ontology that are irrelevant.
SOAP: An XML-based protocol to access objects from Web services.
SOA: An architectural style whose goal is to achieve loose coupling among interacting software agents. A service is a unit of work done by a service provider to achieve desired end results for a service consumer.
User Profile: User information representing his or her preferences and needs.