Retrieval effectiveness of controlled and uncontrolled index terms in INSPEC database

The purpose of this empirical study is to assess the retrieval effectiveness of controlled and uncontrolled index terms in bibliographic database. Two types of index terms were tested in a webbased environment using the operational large-scale INSPEC database. 15 query types used in the study were both controlled terms and uncontrolled index terms derived from inverse document frequency weights. The retrieval effectiveness was evaluated using Precision. The main finding indicates there are statistically significant differences in precision arising from the two types of index terms, the uncontrolled index terms demonstrate better precision than the controlled index terms.