Selecting optimal instantiations of data models - Theory and validation of an ex ante approach

The schema of an information system can significantly impact the ability of end users to efficiently and effectively retrieve the information they need. Obtaining quickly the appropriate data increases the likelihood that an organization will make good decisions and respond adeptly to challenges. This research presents and validates a methodology for evaluating, ex ante, the relative desirability of alternative instantiations of a model of data. In contrast to prior research, each instantiation is based on a different formal theory. This research theorizes that the instantiation that yields the lowest weighted average query complexity for a representative sample of information requests is the most desirable instantiation for end-user queries. The theory was validated by an experiment that compared end-user performance using an instantiation of a data structure based on the relational model of data with performance using the corresponding instantiation of the data structure based on the object-relational model of data. Complexity was measured using three different Halstead metrics: program length, difficulty, and effort. For a representative sample of queries, the average complexity using each instantiation was calculated. As theorized, end users querying the instantiation with the lower average complexity made fewer semantic errors, i.e., were more effective at composing queries. (c) 2005 Elsevier B.V. All rights reserved.

Information literacy for the humanities researcher: A syllabus based on information habits research

This paper reviews the existing literature on the information behavior of researchers in the humanities, in order to develop a set of learning objectives which can be used in the planning of information literacy training programs for this group of library users.

Optimizing the data intensive mediator-based Web services composition

Effectively using heterogeneous, distributed information has attracted much research in recent years. Current web services technologies have been used successfully in some non data intensive distributed prototype systems. However, most of them can not work well in data intensive environment. This paper provides an infrastructure layer in data intensive environment for the effectively providing spatial information services by using the web services over the Internet. We extensively investigate and analyze the overhead of web services in data intensive environment, and propose some new optimization techniques which can greatly increase the system’s efficiency. Our experiments show that these techniques are suitable to data intensive environment. Finally, we present the requirement of these techniques for the information of web services over the Internet.

Quotable value: A case of increasing value

In 2005 Quotable Value was New Zealand’s largest valuation and property information organisation with approximately 230 staff and 22 offices throughout the country. While Government reforms within New Zealand had forced this former Government department to operate in a competitive market, a booming property industry and a number of innovative projects generating new income streams had fuelled Quotable Value’s success and growth. Recent changes in the economic environment, however, and predictions that the property bubble would soon burst, also presented a number of threats. The challenge for Quotable Value was how to sustain and build further growth.

Folk singers during Labour Day march Brisbane 1965

Folk singers during the Labor Day procession, in Brisbane, Australia, May 1965. One person holds a banner relating to the S.S. Binburra

Trucks with banners in Brisbane 1965 during Labor Day procession.

Trucks with banners in Brisbane, Australia, during the Labor Day procession, May 1965.

Participants with Equal pay placard during Labour Day march Brisbane 1965

Participants with Equal pay placard in Brisbane, Australia, during the Labor Day procession, May 1965.

Marchers with banners during Labour Day march Brisbane 1965

Marchers with banners in Brisbane, Australia, during the Labor Day procession, May 1965.