Google Trends is a public web facility of Google Inc., based on Google Search

Google search

Google or Google Web Search is a web search engine owned by Google Inc. Google Search is the most-used search engine on the World Wide Web, receiving several hundred million queries each day through its various services....

, that shows how often a particular search-term is entered relative to the total search-volume across various regions of the world, and in various languages. The horizontal axis of the main graph represents time (starting from some time in 2004), and the vertical is how often a term is searched for relative to the total number of searches, globally. Below the main graph, popularity is broken down by region, city and language. It is possible to refine the main graph by region and time period. On August 5, 2008, Google launched Google Insights for Search

Google Insights for Search

Google Insights for Search is a service by Google similar to Google Trends, providing insights into the search terms people have been entering into the Google search engine. Unlike Google Trends, Google Insights for Search provides a visual representation of regional interest on a country's map. It...

, a more sophisticated and advanced service displaying search trends data.

Background

Google Trends also allows the user to compare the volume of searches between two or more terms.
An additional feature of Google Trends is in its ability to show news related to the search-term overlaid on the chart, showing how new events affect search popularity.

Originally, Google neglected updating Google Trends on a regular basis. In March 2007, internet bloggers noticed that Google had not added new data since November 2006, and Trends was updated within a week. Google did not update Trends from March until July 30, and only after it was blogged about, again. Google now claims to be "updating the information provided by Google Trends daily; Hot Trends is updated hourly."

On August 6, 2008, Google launched a free service called Insights for Search. Insights for Search is an extension of Google Trends and although the tool is meant for marketers, it can be utilized by any user. The tool allows for the tracking of various words and phrases that are typed into Google’s search-box. The tracking device provided a more-indepth analysis of results. It also has the ability to categorize and organize the data, with special attention given to the breakdown of information by geographical areas.

Evidence is provided by Jeremy Ginsberg et al. that Google Trends data can be used to track influenza-like illness in a population. Because the relative frequency of certain queries is highly correlated with the percentage of physician visits in which a patient presents with influenza-like symptoms, an estimate of weekly influenza activity can be reported. Furthermore, it was shown by Tobias Preis

Tobias Preis

Tobias Preis is a German physicist and founder of the Artemis Capital Asset Management GmbH. Born in Limburg an der Lahn, Germany, he researches complex systems with H. Eugene Stanley at Boston University and Dirk Helbing at ETH Zurich. He was awarded a Ph.D...

 et al. that there is a correlation between Google Trends data of company names and transaction volumes of the corresponding stocks on a weekly time scale.

Google Hot Trends

Google Hot Trends is an addition to Google Trends which displays the top 20 hot, i.e., fastest rising, searches (search-terms) of the past hour in the United States. This is for searches that have recently experienced a sudden surge in popularity. For each of the search-terms, it provides a 24-hour search-volume graph as well as blog, news and web search results. Hot Trends has a history feature for those wishing to browse past hot searches. Hot Trends can be installed as an iGoogle

IGoogle

iGoogle , a service of Google, is a customizable Ajax-based startpage or personal web portal . Google originally launched the service in May 2005...

 Gadget. Hot Trends is also available as an hourly Atom

Atom (standard)

The name Atom applies to a pair of related standards. The Atom Syndication Format is an XML language used for web feeds, while the Atom Publishing Protocol is a simple HTTP-based protocol for creating and updating web resources.Web feeds allow software programs to check for updates published on a...

 web feed

Web feed

A web feed is a data format used for providing users with frequently updated content. Content distributors syndicate a web feed, thereby allowing users to subscribe to it. Making a collection of web feeds accessible in one spot is known as aggregation, which is performed by an aggregator...

.

Google Trends for websites

Since 2008 there has been a sub-section of Google Trends which analyses traffic for websites, rather than traffic for search terms. This is a similar service to that provided by Alexa Internet

Alexa Internet

Alexa Internet, Inc. is a California-based subsidiary company of Amazon.com that is known for its toolbar and Web site. Once installed, the toolbar collects data on browsing behavior which is transmitted to the Web site where it is stored and analyzed and is the basis for the company's Web traffic...

.

Google Trends API

An API to accompany the Google Trends service was announced by Marissa Mayer

Marissa Mayer

Marissa Ann Mayer is Vice President of Location and Local Services at the search engine company Google. She has become one of the public faces of Google, providing a number of press interviews and appearing at events frequently to speak on behalf of the company.-Education and career :After...

, vice president of search-products at Google. This was announced in 2007, and so far has not been released.

A few unofficial Google Trends API tools have been released, along with a wiki detailing them and simple access to Google Trends data.

Implications of data

A group of researchers at Wellesley College examined data from Google Trends and analyzed how effective a tool it could be in predicting U.S. Congressional elections in 2008 and 2010. In highly contested races where data for both candidates were available, the data successfully predicted the outcome in 33.3% of cases in 2008 and 39% in 2010. The authors conclude that, compared to the traditional methods of election forecasting, incumbency and New York Times polls, and even in comparison with random chance, Google Trends did not prove to be a good predictor of either the 2008 or 2010 elections.

External links

• Google Hot Trends – Webpage of top 20 search-terms, each linked to 24-hour graph & data.
• Google Trends for Websites