- Major educational fields, fields of study, and professional groupings within USGS.
- Techniques, methods, procedures, or strategies for research, management, collection, or analysis of scientific information in USGS
- Themes, subjects, and concerns for which USGS information resources are relevant
- Product types
- General representation of the information in a resource, such as a map or data set
- Time periods
- Geologic time periods and seasons of the year
- Institutional structures and activities
- Activities, processes, and organizational concepts
The thesaurus is limited in depth and specificity of coverage. It does not attempt to replicate existing controlled vocabularies such as AGI's GeoRef. The intention is to provide sufficient contextual cues for the information seeker to determine the relevance of a resource for his or her concern, not to locate precisely the answer to a specific user question.
Science Topics, a component of the USGS home page from 2005 to 2015, was a browsable index of web resources intended for the public. It augmented traditional search and site-specific browse interfaces in concert with a "USGS by State" and "About USGS" sites, and was specifically intended to work alongside those facilities.
This infrastructure was specifically intended to help people outside USGS find information on USGS web sites without specific knowledge of the organizational structure and operations of the USGS. The interface design was based on the idea that finding information cannot be separated from understanding, so in the process of browsing or searching a user is assisted by seeing relationships among scientific concepts, and learns while searching.
Underpinning this interface were several controlled vocabularies structured as formal thesauri and authority lists, a catalog of web resources appropriate for the intended audience, and software used to create, review, and modify both the controlled vocabularies and the catalog records. The system served as an example of the reapplication of classic library methodologies in the web setting.
Each information resource in the Science Topics catalog was categorized using several index terms. Consequently a document would be listed under each category for which it would be considered a relevant resource. Approximately 2000 web resources were listed in the catalog.
Questions and comments about the thesaurus or the USGS implementation of it can be sent to firstname.lastname@example.org.