With the help of National Science Foundation funding, Cleverdon started a series of projects in 1957 that lasted for about 10 years in which he and his colleagues set the stage for information retrieval research.
Test collections and evaluation measures based on precision and recall are driving forces behind modern research on search systems.
Not only did Cleverdon's Cranfield studies introduce experimental research into computer science, the outcomes of the project also established the basis of the automatic indexing as done in today's search engines.
In the Cranfield 2 Report, Cleverdon said: This conclusion is so controversial and so unexpected that it is bound to throw considerable doubt on the methods which have been used (...) A complete recheck has failed to reveal any discrepancies (...) there is no other course except to attempt to explain the results which seem to offend against every canon on which we were trained as librarians.
Cyril Cleverdon also ran, for many years, the Cranfield conferences, which provided a major international forum for discussion of ideas and research in information retrieval.