Navigation Logs : Summary

Summary tables compare the number of terms seen and selected by various criteria, for example distance from the starting-point or type of relationship followed. They can be produced for individual users, or averaged over a group. The following tables summarise information about all users participating in the first two evaluation experiments.

Average number of terms seen and selected, by distance from starting point

(Note that some users were prepared to navigate up to five moves away from their starting-point, and were evidently still finding terms which they thought potentially useful.) 
      Distance Terms_seen  Terms_chosen  Row %age
      -------- ---------- ------------- ---------
           0        80.66          3.28         4
           1        20.18          2.74        14
           2        25.28          1.64         6
           3        12.90          1.41        11
           4         6.77           .61         9
           5         1.66           .05         3
           6          .30           .00         0
              ----------- ------------- ---------
      Overall      147.77          9.74       6.5

Average number of terms seen and selected, by relationship followed

(Note that users showed no clear preference for any one relationship: the larger proportion of associative relationships recorded here reflects the larger proportion in the thesaurus as a whole.) 
  Relationship  Terms_seen  Terms_chosen  Row %age
  ------------  ----------- ------------- -------- 
      Broader         6.23           .51         8
     Narrower         9.54          1.02        11
  Associative        51.38          4.92        10
               ----------- -------------  --------
      Overall        67.10          6.46        10
A general finding was that users selected on average no more than 10% of the terms which they saw during thesaurus navigation, and in practice those who were more selective were also more successful. So far the data provides little basis for weighting procedures to be used in automatic query enhancement.

See also individual navigation logs.