Reciprocal Rank
Mean reciprocal rank used as score:
- reciprocal of the rank at which first correct response returned (or 0 if none)
- for run, take mean over questions� scores
Properties
- equivalent to average precision if one relevant
- averages well
- no correct answer handled gracefully
- only 6 possible values per question
- no credit for multiple correct answers
- no credit for system knowing it doesn�t know