Google has formally announced the “Knowledge Graph,” its way of providing results about “things”. We’ve reported on the products of this a couple of times, as Google has been testing them.

An example would be when you search for a band, and Google puts some boxes on the side of the search results page with some specific info about that band. Likewise for movies, actors, books and people. According to the company, it also includes landmarks, cities, sports teams, buildings, geographical features, celestial objects, works of art, and more.

The main theme of the Knowledge Graph, as Google is presenting it, is that it is making Google smarter and better at giving you answers. Better at distinguishing what you mean by certain queries, which may come with more than one meaning. Googles gives the example of Taj Mahal: “do you mean Taj Mahal the monument, or Taj Mahal the musician? Now Google understands the difference, and can narrow your search results just to the one you mean.”

Google put out the following video talking about it:

This appears to be the big Google change that was discussed in a popular Wall Street Journal article in March, which we wrote about here. In our take, we talked about how Google is doing more to keep people from having to leave its own pages, by providing more info on them – basically, users have less reasons to click through to other sites. It’s wroth noting, however, that Google SVP, Engineering, Amit Singhal, indicated at SMX London this week, that Google’s Search Plus Your World personalized results are generating greater clickthrough rates for search results.

According to the WSJ article, Google’s 2010 acquisition of Metaweb plays a significant role in what is now known as the Knowledge Graph.

Metaweb came with a big open database of 12 million things (including movies, books, TV shows, celebrities, locations, companies and more) called Freebase. There’s more to it than that though.

“Google’s Knowledge Graph isn’t just rooted in public sources such as Freebase, Wikipedia and the CIA World Factbook,” says Singhal. “It’s also augmented at a much larger scale—because we’re focused on comprehensive breadth and depth. It currently contains more than 500 million objects, as well as more than 3.5 billion facts about and relationships between these different objects. And it’s tuned based on what people search for, and what we find out on the web.”

I’m guessing there’s some Google Squared in there too.

“How do we know which facts are most likely to be needed for each item? For that, we go back to our users and study in aggregate what they’ve been asking Google about each item,” explains Singhal. “For example, people are interested in knowing what books Charles Dickens wrote, whereas they’re less interested in what books Frank Lloyd Wright wrote, and more in what buildings he designed.”

The Knowledge Graph is “gradually” rolling out to U.S. users in English.