Containing thousands of genocide-related concepts and experiences, the USC Shoah Foundation Thesaurus is one of the first of its kind. It lists the indexing terms used to describe the video testimonies and arranges them hierarchically under broad headings. These terms have been assigned directly to digital time codes within testimonies where the specific topics are discussed, in much the same way that book index entries specify the page numbers where topics are covered.
The Thesaurus evolved over time and grew in volume as the testimonies were indexed. While some indexing terms have been drawn from existing controlled vocabularies, the depth of content within the collection required the creation of local indexing terms to facilitate access at a more precise level.