The Knowledge Graph is used by Google Search to help users discover information more quickly and easily. The Knowledge Graph has millions of entries that describe real-world entities like people, places, and things. These entities form the nodes of the graph, and are called Knowledge Graph Entities.
Programmable Search Engine supports using Knowledge Graph Entities to
- Define which pages the search engine searches.
- Create Refinements to narrow down search results within a search engine.
Defining a search engine with Knowledge Graph Entities
Using the "Setup > Basic" page of the Programmable Search Engine Control Panel, you can configure your search engine to restrict search to only those web pages that are about specific Knowledge Graph Entities.
For example, to define a search engine that searches the entire web for pages about Alphabet companies, first set "Search the entire web" to "ON", then use the "Restrict Pages using Knowledge Graph Entities" selector to add the relevant Knowledge Graph Entities to your search engine configuration.
This search engine will return any page that mentions any of the five companies. Try it out here: https://cse.google.com/cse?cx=000888210889775888983:b2bhygxt4le
You can also combine "Sites to search" and Knowledge Graph Entities to define your search engine. For example, to create a search engine that searches every page about the Entity "Pittsburgh" in Wikipedia, add en.wikipedia.org to the "Sites to search" and select the relevant Entity:
Refinements based on Knowledge Graph Entities
On the "Search features > Refinements" page of the Programmable Search Engine Control Panel, Knowledge Graph Entities can be added to a search engine Refinement. When the Refinement is selected, only pages that mention the Refinement's entities (and that match the top-level search engine definition) will be returned.
For example, we can define a search engine to be about the Knowledge Graph Entity "basketball":
Then add refinements for things like NBA, WNBA, College, Olympic basketball, and basketball equipment. For example, this refinement will return pages that are about both Basketball (from the top-level search engine definition) and Sports Equipment, Shoes, or Jerseys:
Try it out here: https://cse.google.com/cse?cx=000888210889775888983:-nzsrilglze