The advanced search fields in OSTI.GOV use term search. Term search applies the provided search terms exactly as entered, with no concept mapping, and allows use of Boolean operators. If you are searching for a very specific title, author, or keyword, the term search may be more appropriate.
The default search for words or phrases entered into the basic search box from the homepage or at the top of every screen in OSTI.GOV uses semantic search, and utilizes a technique called keyword-to-concept mapping. The term(s) you search will be mapped to related scientific concepts based on a thesaurus developed by OSTI, allowing you to retrieve results related to your search term, but also to explore narrower and similar concepts. Boolean operators are ignored in the semantic search so your term(s) can be easily mapped to other concepts.
This technique is an expansion of your search and will generally return a larger number of results.
Example: Using semantic search, a search for wind energy would be expanded to approximately 48 terms associated with wind and energy, including these: