Google described it as an experimental tool enabling the user to find queries with a similar pattern to a target data series.
Users can upload data sets (by state or time series, and Google Correlate will compute the “Pearson Correlation Coefficient” between your time series and the frequency time series for every query in its database.
Previously only available in the U.S., Google announced today that the service is being extended into 49 new countries.
“Since our initial launch, we've graduated to Google Trends and we've seen a number of great applications of Correlate in several domains, including economics (consumer spending, unemployment rate and housing inventory), sociology and meteorology,” says Google software engineer Matt Mohebbi. “The correspondence of gas prices and search activity for fuel efficient cars was even briefly discussed in a Fox News presidential debate and NPR recently covered correlations related to political commentators.”
“Health has always been an area of particular interest to our team (Matt Mohebbi, Julia Kodysh, Rob Schonberger and Dan Vanderkam),” says Mohebbi. “Correlate was inspired by Google Flu Trends and many of us worked on both systems. So we were very excited when the BioSense division at the CDC published a page which shows correlations between some of their national trends in patient diagnosis activity and Google search activity. With just three years of weekly data, relevant search terms are surfaced. For example, the time series for bloody nose surfaces ‘bloody snot’ and ‘blood in snot’.”
“While these terms shouldn't come as a surprise, there are others which are more interesting, including searches related to static electricity, dry skin, and red cheeks,” says Mohebbi. “Of course, correlation is not causation but we hope that Correlate can be used as a method for researchers to generate new hypotheses with their data.”
For more on Google Correlate, check out this FAQ page.