Information retrieval has changed considerably in the last years with the expansion of the Web (World Wide Web) and the advent of modern and inexpensive graphical user interfaces and mass storage devices. How does one find anything on the Internet? There are essentially four methods of information retrieval on Internet: browsing, consulting an index, word of mouth, or posting a request.

Problem in information retrieval
The key problems in Internet information retrieval, in particular concerned with ill-defined information requirements, concept interpretation in searching and text representation in indexing. The main objective of information retrieval is to facilitate the effective communication of desired information between a human generator of information and the human user. This communication takes place in an information system.

Aims
The present paper aims to analyse and suggest solutions to key problems in online information retrieval, in particular concerned with the search of information problems on Internet.

User model of information retrieval
Information retrieval research has developed in a fairly complex manner around the classic but effective vector space model, abstracting from single keywords to cluster of keywords and other increasingly abstract objects, in order to improve discriminating performance. User model from the psychological point of view represent the category of keywords with associated score according to the "mental representation" present in the model. We use conceptual graphs to model the user's search goal on Internet. The nodes represent keywords, annotated with frequency of usage; the links represent the distance between keywords in the model. The task isto transform user requests into queries by understanding the information problem or the underlying goal or problem.

Design and usability testing
Efficient usability testing involves choosing the most appropriate methods for the problem at hand. The purpose of testing is to provide design support and the emphasis should therefore be on obtaining the maximum design-related information for the testing effort. In the present discussion the research is reserved for that more general activity that is directed towards the accumulation of general principles. When specific answers to very specific questions are required the usability testing is more appropriate.

References

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