| Similarity |
Page |
Snapshot |
| 30 |
In practice,one seeks some sort of optimal trade off between representation and discrimination
...The emphasis on representation leads to what one might call a document orientation:that is,a total preoccupation with modelling what the document is about
...This point of view is also adopted by those concerned with defining a concept of information,they assume that once this notion is properly explicated a document can be represented by the information it contains [37]...The emphasis on discrimination leads to a query orientation
...Automatic keyword classification Many automatic retrieval systems rely on thesauri to modify queries and document representatives to improve the chance of retrieving relevant documents
... |
| 5 |
frequency of occurrence and co occurrence of index terms in the relevant and non relevant documents
...Chapter 7:Evaluation here I give a traditional view of the measurement of effectiveness followed by an explanation of some of the more promising attempts at improving the art
...Chapter 8:The Future contains some speculation about the future of IR and tries to pinpoint some areas of research where further work is desperately needed
...Information retrieval Since the 1940 s the problem of information storage and retrieval has attracted increasing attention
...In principle,information storage and retrieval is simple
...When high speed computers became available for non numerical work,many thought that a computer would be able to read an entire document collection to extract the relevant documents
... |
| 7 |
systems store only a representation of the document or query which means that the text of a document is lost once it has been processed for the purpose of generating its representation
...When the retrieval system is on line,it is possible for the user to change his request during one search session in the light of a sample retrieval,thereby,it is hoped,improving the subsequent retrieval run
...Secondly,the processor,that part of the retrieval system concerned with the retrieval process
... |
| 106 |
account of past performance
...Consider now a retrieval strategy that has been implemented by means of a matching function M
...It is the aim of every retrieval strategy to retrieve the relevant documents A and withhold the non relevant documents A
...the decision procedure M Q,D T >0 corresponds to a linear discriminant function used to linearly separate two sets A and A in R [t]...M Q 0,D >T whenever D [[propersubset]]A and M Q 0,D <T whenever D [[propersubset]][[Alpha]]The interesting thing is that starting with any Q we can adjust it iteratively using feedback information so that it will converge to Q 0
... |
| 189 |
The time is ripe for another attempt at using natural language to represent documents inside a computer
...It has never been assumed that a retrieval system should attempt to understand the content of a document
...Such an approach would make feedback a major tool
...Future developments Much of the work in IR has suffered from the difficulty of comparing retrieval results
... |
