| Similarity |
Page |
Snapshot |
| 60 |
differences in the scale and in the use to which a classification structure is to be put
...In the case of scale,the size of the problem in IR is invariably such that for cluster methods based on similarity matrices it becomes impossible to store the entire similarity matrix,let alone allow random access to its elements
...When a classification is to be used in IR,it affects the design of the algorithm to the extent that a classification will be represented by a file structure which is 1 easily updated;2 easily searched;and 3 reasonably compact
...Only 3 needs some further comment
...Conclusion Let me briefly summarise the logical structure of this chapter
...This chapter ended on a rather practical note
... |
| 59 |
comparison is between where n 1 <n 2 <...In any case,if one is willing to forego some of the theoretical adequacy conditions then it is possible to modify the n A HREF REF
...Another comment to be made about n log n methods is that although they have this time dependence in theory,examination of a number of the algorithms implementing them shows that they actually have an n 2 dependence e
...In experiments where we are often dealing with only a few thousand documents,we may find that the proportionality constant in the n log n method is so large that the actual time taken for clustering is greater than that for an n 2 method
...The implementation of classification algorithms for use in IR is by necessity different from implementations in other fields such as for example numerical taxonomy
... |
| 186 |
behaviour of any one of the components depends in only an aggregate way on the behaviour of the other components
...2
...On the file structure chosen and the way it is used depends the efficiency of an information retrieval system
...Inverted files have been rather popular in IR systems
...There are many more problems in this area which are of interest to IR systems
...3
...So far fairly simple search strategies have been tried
... |
