NIST TREC-9 SDR Web Site (2000) states that: The results of the TREC-9 2000 SDR evaluation presented at TREC on November 14, 2000 showed that retrieval performance for sites on their own recognizer transcripts was virtually the same as their performance on the human reference transcripts.
each query q ∈ Q is presented to the system only once, independent of the number of occurences of q in the transcriptions.