The ERIC Thesaurus contains a total of 11,721 terms. There are 4,520 Descriptors and 7,068 Synonyms. There are also 133 Dead terms which are no longer used as Descriptors but remain in the Thesaurus to aid in searching older records. The ERIC Thesaurus was last updated in October 2015. The updated Thesaurus includes 19 new Descriptors, 28 new Synonyms, and changes to 17 existing terms.