The Cranfield experiments were computer information retrieval experiments conducted by Cyril W. Cleverdon at Cranfield University in the 1960s, to evaluate the efficiency of indexing systems.
They represent the prototypical evaluation model of information retrieval systems, and this model has been used in large-scale information retrieval evaluation efforts such as the Text Retrieval Conference (TREC).
References
Cranfield experiments Wikipedia(Text) CC BY-SA