IR Glossary

This glossary collects terminology specific to the field of information retrieval. It is an early draft. If you find any inaccuracies or errors, please don't hesitate to open an issue.

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CLEF lab. A scientific event organizing shared tasks on a given retrieval domain as part of the CLEF conference (see also NTCIR evaluation workshop, TREC track).

IR. Information Retrieval.

NTCIR evaluation workshop. A scientific event organizing shared tasks on a given retrieval domain as part of the NTCIR conference (see also CLEF lab, TREC track).

Q0. In almost all run files of shared tasks organized as part of TREC tracks, the string "Q0" is the literal content of the second column, repeated over and over for no apparent reason. This column was intended to identify the query number within the topic, anticipating that TREC topics that are formatted in TREC's standard topic format might contain more than one query. This was hardly ever the case, so that the topics of most shared tasks have only one query, and thus the second column of their run files is always "Q0". The unused literal is kept for consistency of the run file format with the TREC tools. An exception includes the podcasts track, which makes actual use of the second column.

Ian Soboroff: The first rule of TREC is that Q0 is a literal “Q0”.

qrel. Abbreviation for "query relevance judgment". Plural: "qrels".

TREC track. A scientific event organizing shared tasks on a given retrieval domain as part of the TREC conference (see also CLEF lab, NTCIR evaluation workshop).