Concepts
Similar pages
| Similarity |
Page |
Snapshot |
| 176 |
conjoint structure
...The analysis is not limited to the two factors precision and recall,it could equally well be carried out for say the pair fallout and recall
...Presentation of experimental results In my discussion of micro,macro evaluation,and expected search length,various ways of averaging the effectiveness measure of the set of queries arose in a natural way
...In this section the discussion will be restricted to single number measures such as a normalised symmetric difference,normalised recall,etc
...The measurements we have therefore are Za Q 1,Za Q 2,... |
| 179 |
that Di is continuous and that it is derived from a symmetric distribution,neither of which is normally met in IR data
...It seems therefore that some of the more sophisticated statistical tests are inappropriate
...The way it works is as follows:Let Za Q 1,Za Q 2,...P Za >Zb P Za <Zb [1]2 Under this hypothesis we expect the number of pairs which have Za >Zb to equal the number of pairs which have Za <Zb
...In IR this test is usually used as a one tailed test,that is,the alternative hypothesis prescribes the superiority of retrieval under condition a over condition b,or vice versa
...The use of the sign test raises a number of interesting points
... |
| 173 |
It will turn out that the F which is appropriate can be simply transformed into an additive representation
...Explicit measures of effectiveness I shall now argue for a specific form of [[Phi]]i and F,based on a model for the user
...Since we have assumed that effectiveness is determined by precision and recall we have committed ourselves to the importance of proportions of documents rather than absolute numbers
... |
|
|
