Understanding the retinal basis of vision across species

The vertebrate retina first evolved some 500 million years ago in ancestral marine chordates. Since then, the eyes of different species have been tuned to best support their unique visuoecological lifestyles. Visual specializations in eye designs, large-scale inhomogeneities across the retinal surface and local circuit motifs mean that all species' retinas are unique. Computational theories, such as the efficient coding hypothesis, have come a long way towards an explanation of the basic features of retinal organization and function; however, they cannot explain the full extent of retinal diversity within and across species. To build a truly general understanding of vertebrate vision and the retina's computational purpose, it is therefore important to more quantitatively relate different species' retinal functions to their specific natural environments and behavioural requirements. Ultimately, the goal of such efforts should be to build up to a more general theory of vision

Abstract Summary of WWW Characterizations

To date there have been a number of efforts that attempt to characterize various aspects of the World Wide Web. This paper presents a summary of these efforts, highlighting regularities and insights that have been discovered across the variety of access points available for instrumentation. Characterizations that are derived from client, proxy, and server instrumentation are reviewed as well as efforts to characterize the entire structure of the WWW. Given the dynamic nature of the Web, it may be surprising for some readers to find that many properties of the Web follow regular and predictable patterns that have not changed in form over the Web's lifetime. Understanding these aspects as well as those that vary is critical to designing a better Web, and as a direct consequence, creating a more enjoyable user experience

Predicting Document Access in Large Multimedia Repositories

Network-accessible multimedia databases, repositories, and libraries are proliferating at a rapid rate. A crucial problem for these repositories remains timely and appropriate document access. In this article, we borrow a model from psychological research on human memory, which has long studied retrieval of memory items based on frequency and recency rates of past item occurrences. Specifically, the model uses frequency and recency rates of prior document accesses to predict future document requests. The model is illustrated by analyzing the log file of document accesses to the Georgia Institute of Technology World Wide Web (WWW) repository, a large multimedia respository exhibiting high access rates. Results show that the model predicts document access rates with a reliable degree of accuracy. We describe extensions to the basic approach that combine the recency and frequency analyses and which incorporate respository structure and document type. These results have implications for the formulation of descriptive user models of information access in large repositories. In addition, we sketch applications in the areas of design of information systems and interfaces and their document-caching algorithms

Using the Web as a survey tool: results from the second WWW user survey

This paper presents the initial results from the second World-Wide Web User Survey, which was advertised and made available to the Web user population for 38 days during October and November 1994. The survey is built on our architecture and Web technologies, which together offer a number of technical and surveying advantages. In particular, our architecture supports the use of adaptive questions, and supports methods for tracking users ’ responses across different surveys, allowing more in-depth analyses of survey responses. The present survey was composed of three question categories: general demographic questions, browsing usage, and questions for Web information authors. In addition, we added an additional, experimental category addressing users ’ attitudes toward commercial use of the Web and the Internet. In just over one month, we received over 18,000 total responses to the combined surveys. To the best of our knowledge, the number of respondents and range of questions make this survey the most reliable and comprehensive characterization of WWW users to date. It will be interesting to see if and how the user trends shown in our results change as the Web gains in global access and popularity

Results from the first world-wide web user survey

The explosion of World-Wide Web (WWW) across the Internet is staggering, both in terms of number of users and the amount of activity. However, to date, no reliable characterization exists of WWW users. In this paper, we report results from a survey that was posted on the Web for a month, in January of 1994. There were several goals motivating our survey. First, we wished to demonstrate a proof of concept for WWW technologies as a useful survey medium. Second, we wanted to beta-test the design and content of surveys dealing with the Web. Third, as mentioned, we hoped to begin to describe the range of Web users. In one month, we had over 4,700 respondents to our survey. Their responses helped us to begin to characterize WWW users, their reasons for using the WWW, and their opinions of WWW tools and technologies