Maki, William S., Lauren N. McKinley, and Amber G. Thompson. "Semantic Distance Norms Computed from an Electronic Dictionary (WordNet)." Behavior Research Methods, Instruments, & Computers 36, no. 3 (2004): 421-431.
Maki et al. describe how they created a database in which they offer semantic distance values for approximately 50,000 word pairs. They describe how they calculated these values and how they conducted experiments in which human subjects were asked to judge semantic distances. Semantic distance, Maki et al. report, is distinct from other measures of word pair relatedness. The database is available online via the Psychonomic Society Archive of Norms, Stimuli, and Data, at http://www.psychonomic.org/archive.