In a major step toward semantic search, Google started rolling out “Knowledge Graph”, a SERP-integrated display providing supplemental object about certain people, places, and things. “Knowledge panels” would be expected to appear on more and more Search results.
The Knowledge Graph is a knowledge base used by Google to enhance its search engine’s search results with semantic-search information gathered from a wide variety of sources. Knowledge Graph display was added to Google’s search engine in 2012, starting in the United States, having been announced on May 16, 2012. It provides structured and detailed information about the topic in addition to a list of links to other sites. The goal is that users would be able to use this information to resolve their query without having to navigate to other sites and assemble the information themselves. The short summary provided in the knowledge graph is often used as a spoken answer in Google Now searches.
According to some news websites, the implementation of Google’s Knowledge Graph has played a role in the page view decline of various language versions of Wikipedia.
According to Google, the information in the Knowledge Graph is derived from many sources, including the CIA World Factbook, Wikidata, and Wikipedia. The feature is similar in intent to answer engines such as Wolfram Alpha and efforts such as Linked Data and DBpedia.
As of 2012, its semantic network contained over 570 million objects and more than 18 billion facts about and relationships between different objects that are used to understand the meaning of the keywords entered for the search.