The Knowledge Graph pulled in information from structured sources like Freebase, Wikidata and Wikipedia, while the Knowledge Vault is an accumulation of facts from across the entire web, including unstructured sources. "Facts" in Knowledge Vault also include a confidence value, giving the capability of distinguishing between knowledge statements that have a high probability of being true from others that may be less likely to be true (based on the source that Google obtained the data from and other factors).
The concept behind the Knowledge Vault was presented in a paper authored by a Google Research team.
Google has indicated that Knowledge Vault is a research paper and not an active product in development, as of August 2014.
- Hal Hodson (2014-08-04). "Google's fact-checking bots build vast knowledge bank". New Scientist.
- Dong, X. L., Gabrilovich, E., Heitz, G., Horn, W., Lao, N., Murphy, K., Strohman, T., Sun, S. & Zhang, W. (2014). Knowledge Vault: A Web-scale approach to probabilistic knowledge fusion. doi:10.1145/2623330.2623623. Authors alphabetically listed, Murphy, K. is the corresponding author.
- Sterling, Greg (2014-08-25). "Google "Knowledge Vault" To Power Future Of Search". Search Engine Land. Retrieved 2015-06-25.
Google yesterday indicated that the 'Knowledge Vault' was misrepresented ... and is not an active Google product in development.