4. The method of claim 1 , wherein using the user input to inform future selections of pairs of candidate scoring functions from the group of candidate scoring functions comprises: generating a ranking for the candidate scoring functions in the group based at least in part on the user input; and selecting, for evaluation by one or more other users, one or more candidate scoring functions in the group based at least in part on the ranking for the candidate scoring functions in the group.
4. The method of claim 1 , wherein using the user input to inform future selections of pairs of candidate scoring functions from the group of candidate scoring functions comprises: generating a ranking for the candidate scoring functions in the group based at least in part on the user input; and selecting, for evaluation by one or more other users, one or more candidate scoring functions in the group based at least in part on the ranking for the candidate scoring functions in the group. 11. The method of claim 4 , further comprising: receiving a second query; selecting a third candidate scoring function and a fourth candidate scoring function from a top number of scoring functions in the ranking for the candidate scoring functions in the group; presenting search results, which are responsive to the second query, ordered according to scores from the third candidate scoring function; presenting the search results, which are responsive to the second query, ordered according to scores from the fourth candidate scoring function; receiving second user input selecting one of the third and fourth candidate scoring functions over the other; and updating the ranking for the candidate scoring functions in the group based at least in part on the second user input.