Google's ability to understand the complexities of synonyms, related terms, and categorization have improved dramatically over time. A recent addition to the SERP takes advantage of this understanding to provide a list of related searches for users. In addition to triggering with searches for general categories, Google provides suggestions in artist, author, movie, and celebrity searches.
The Search Element & How It Works
As explained in the official release, Google's new feature takes the improved understanding of topic interrelation to provide users with a lineup of related searches when they search for a broad topic. Searching for "cheeses," as just one example, provides the following list:
This list of references appears at the bottom of your SERP results, but if you click on any one of the sub-categories, the "top references" search element moves to the top of the page and search results for the selected term are displayed. You can then quickly click around on the different sub-categories, important figures, or sub-types for more information.
Google has also added a "related search" element to several other search types, including the search for a movie title, or a celebrity, artist, or author's name. This creation/creator-centric search will result in a visual search bar at the bottom of the SERP. For example, looking up my good buddy Edward Norton gives these results:
Unlike the "top references" for category searches, these specialized book, movie, artwork, and contributor bars disappear when you click through to a new suggested search.
Simpso—Er, Bing Already Did It
Just so it's completely clear, Google wasn't the first search site to come up with this idea. Bing has provided a "related search" section in its left column for months, while Yahoo has long provided an "also try" segment at the top of search results. What will differentiate Google is its ability to understand the categorical relations and to provide a stronger visual element.
Google is pulling information from pages across the web, but certain trusted sources have served to create categorical data. In cases where data was mined largely from select sources (such as IMDB or Wikipedia), Google will notify the user in a "sources include" segment at the bottom of the "top references" element. Beyond trusting established sources, Google is using data from its 2-year-old Google Squared experiment.
It's hard to say if Google's suggestions will really be superior than those provided by Bing, but considering the lower click-through to SERP results for Google (when compared to Bing and Yahoo), the new SERP element is certainly a wise choice. Bing, meanwhile, will have to add some visual elements to counter-copy Google – matching Google's one-up on suggested searches.