Quantified Interference: Information Theory and Information Flow

The paper investigates which of Shannon’s measures (entropy, conditional entropy, mutual information) is the right one for the task of quantifying information flow in a programming language. We examine earlier relevant contributions from Denning, McLean and Gray and we propose and motivate a specific quantitative definition of information flow. We prove results relating equivalence relations, interference of program variables, independence of random variables and the flow of confidential information. Finally, we show how, in our setting, Shannon’s Perfect Secrecy theorem provides a sufficient condition to determine whether a program leaks confidential information.

Towards institution-wide online teaching and learning systems: trends, drivers and issues

Universities worldwide are consolidating and enhancing their commitments to various models of e-learning. These activities are leading to the adoption of corporate-wide e-learning systems, and accompanying changes in structures, processes and infrastructure requirements. The professed ideal is to identify narrowly defined corporate IT solutions which can deliver the full range of educational, administrative and student support features to meet the organisational need to expand e-learning activities globally. The trend seems to be away from locally driven and controlled IT development and adoption towards investments in Instructional Management Systems (IMS). In reality, however, universities generally are developing and using a broader array of solutions to meet their needs than may be deemed desirable under a more centralised, corporatised IT approach. This paper examines these trends by analysing the drivers shaping corporate approaches to IT implementation, and reflects critically on some of the educational, economic and organisational tensions and issues evident in institutional approaches to establishing such systems. The paper highlights the ongoing need for innovative, dynamic organisational solutions to progress the e-learning agenda, and the thoughtful reconciliation of centralised and decentralised approaches to achieving desired ends.

Marketing information sources and the performance of Australian businesses

This study investigated the various sources of information used by business organisations and their association with business performance indicators. The results showed that larger Australian companies predominantly used various internal and external secondary data sources of information, followed by formal primary marketing research. The study indicated an association between market share and the use of competitors, advertising agencies, and sales promotion agencies as sources of information, while overall financial performance was associated with the use of competitors and media/trade publications.

Developing effective advertising self-regulation in Australia: reflections on the old and new systems

The regulation of advertising is a controversial and difficult process. Over the past three decades, two attempts have been made in Australia to produce more acceptable ads. This paper reviews these systems using a macro framework for analysis which contextualises advertising in society. The systems have the fundamental process of handling complaints about advertising in common, however there are advantages and disadvantages of each and these are discussed. Important insights for the development of regulation of advertising are presented together with critical implications for the future of the industry.

Information navigation and knowledge discovery in virtual communities

Over the past decade, advances in the Internet and media technology have literally brought people closer than ever before. It is interesting to note that traditional sociological definitions of a community have been outmoded, for community has extended far beyond the geographical boundaries that were held by traditional definitions (Wellman & Gulia, 1999). Virtual or online community was defined in such a context to describe various forms of computer-mediated communication (CMC). Although virtual communities do not necessarily arise from the Internet, the overwhelming popularity of the Internet is one of the main reasons that virtual communities receive so much attention (Rheingold, 1999). The beginning of virtual communities is attributed to scientists who exchanged information and cooperatively conduct research during the 1970s. There are four needs of participants in a virtual community: member interest, social interaction, imagination, and transaction (Hagel & Armstrong, 1997). The first two focus more on the information exchange and knowledge discovery; the imagination is for entertainment; and the transaction is for commerce strategy. In this article, we investigate the function of information exchange and knowledge discovery in virtual communities. There are two important inherent properties embedded in virtual communities (Wellman, 2001):

Technology and management systems for digital rights and content: the editors friend

Since the late 1980s, when authors began to deliver typescripts to their publishers on disk, the process of editing and publishing books has been in an almost constant state of change. Not only has digital technology enabled a conflation of book production processes, but books themselves are increasingly available in a wider choice of delivery modes. From traditional hard cover and paperback books, to digital files formatted for printing on desktop printers, to files specifically prepared for delivery via hand-held electronic book-reading devices, to text designed to be read on screen (incorporating hyperlinks that facilitate the reader's ability to navigate around the text and between texts), the consumer now has potential myriad choices for delivery of their chosen content. And the publisher, it seems, has myriad ways to deliver content and to seek and satisfy new markets. As well as opportunities, these changes have caused disruption to the traditional supply chain.

This paper focuses on changes to the role of the editor caused by the digitisation of the publishing industry.

Information leakage and informed trading around unscheduled earnings announcements

While there has been much judicial discussion regarding the competency of Australia's continuous disclosure regime with reference to contemporaneous international standards, there has to date been limited empirical analysis of the Australian system's effectiveness in preventing selective disclosure and information leakage. This paper presents an empirical study of information content and trading behaviour around unscheduled earnings announcements - comprising of profit upgrades, profit warnings and neutral trading statements - made by ASX-listed companies during 2004. The contention is that informed trading impacts on the stock returns and trading volumes of listed entities, and hence abnormal returns or trading volumes observed prior to an announcement provide evidence of information leakage. The paper models a range of factors that potentially influence firm disclosure practices and contribute to the level information asymmetry in the market during the pre- announcement period. Previous research has investigated the influence of firm size and information content in contributing to information leakage. This study further considers the variables of firm growth, capital structure and industry group.