South by Southwest: About Google Trends

About Google Trends
With Google Trends, you can compare the world’s interest in your favorite topics. Enter up to five topics and see how often they’ve been searched on Google over time. Google Trends also shows how frequently your topics have appeared in Google News stories, and in which geographic regions people have searched for them most.

How does Google Trends work?

How accurate and up-to-date is the information provided by Google Trends?

When will Google Trends be available for my country or language?

About Hot Searches
With Hot Searches, you can see a snapshot of what’s on the public’s collective mind by viewing the fastest-rising searches for different points of time. You can see a list of today’s top 40 fastest-rising search queries in the U.S. You can also select a recent date in history to see what the top rising searches were and what the search activity looked like over the course of that day. Hot Searches are updated hourly.

How does Hot Searches work?

Is the list of Hot Searches comprehensive?

Working with Google Trends

How many terms can I compare? And what other functionality is available?

How is the data scaled?

Is the News reference volume graph scaled?

Is the data normalized?

Do the numbers on the graph reflect actual search traffic numbers?

I see a number next to my search term at the top of the graph. What does it mean?

When comparing two or more search terms, I sometimes see results with all zeros. Why?

Is there a way to adjust how the terms are ranked and scaled?

How does counting and ranking of the top regions, cities, and languages work, and are they scaled differently?

How is information gathered to determine the regions, cities, and languages?

How do I change the time frame, region, or sub-region of the results?

Is there a way to export the data?

How does the geographical assignment change from 1/1/2011 affect the data I see?

Privacy and Terms of Use

When is it okay to use the information I find on Google Trends?

This tool makes search information public. What about my personal search data?

1. How does Google Trends work?
Google Trends analyzes a portion of Google web searches to compute how many searches have been done for the terms you enter, relative to the total number of searches done on Google over time. We then show you a graph with the results – our Search Volume Index graph.
Located beneath the Search Volume Index graph is our News reference volume graph. This graph shows you the number of times your topic appeared in Google News stories. When Google Trends detects a spike in the volume of news stories for a particular search term, it labels the graph and displays the headline of an automatically selected Google News story written near the time of that spike. Currently, only English-language headlines are displayed, but we hope to support non-English headlines in the future.
Below the search and news volume graphs, Trends displays the top regions, cities, and languages in which people searched for the first search term you entered.

2. How accurate and up-to-date is the information provided by Google Trends?
The data Trends produces may contain inaccuracies for a number of reasons, including data-sampling issues and a variety of approximations that are used to compute results. We hope you find this service interesting and entertaining, but you probably wouldn’t want to write your Ph.D. dissertation based on the information provided by Trends.
The information provided by Trends is updated daily, and Hot Searches is updated hourly.

3. When will Google Trends be available for my country or language?
Currently, Google Trends is only available in English and in Chinese. Hot Searches is only available in English, but both Singapore and India show information specific to their regions. We hope to roll out Google Trends in other regions and languages in the future.

4. How does Hot Searches work?
Hot Searches reflects what people are searching for on Google today. Rather than showing the most popular searches overall, which would always be generic terms like “weather,” Hot Searches highlights searches that experience sudden surges in popularity, and updates that information hourly. Our algorithm analyzes millions of web searches performed on Google and displays those searches that deviate the most from their historic traffic pattern. The algorithm also filters out spam and removes inappropriate material. For each search, Hot Searches shows related searches and a Search Volume Index graph. The page also displays news, blog posts, and web results to give context about why a search may be appearing on the Hot Searches list. You can also choose a date in the past to see what the top Hot Searches were for that date by clicking change date.

5. Is the list of Hot Searches comprehensive?
No. We know there may be numerous queries that experience sudden surges in popularity, but Hot Searches only highlights the top 40 such queries. You can view all 40 searches by clicking More Hot Searches; this list is updated throughout the day. You can also get this list through a feed. To do so, click Site Feed after you’ve clicked More Hot Searches, and follow the instructions.

6. How many terms can I compare? And what other functionality is available?
You can compare up to five terms by separating each one with a comma. For example, to compare “boots” and “sneakers”, simply enter boots, sneakers and click Search Trends.
To see how many searches contained either term, list them and separate with a vertical bar ( | ):
boots | sneakers
To see how many searches were done for either “snow boots” or “sneakers”, use parentheses around the multi-word term: (snow boots) | sneakers.
You can also exclude terms from your search by using the minus sign. For instance, to see how many searches contained the term “boots” but not “hiking”, enter boots-hiking.
To restrict your results to only those searches that contain your terms in the specific order you’ve entered them, you can put your terms in quotation marks: "snow boots". (By default, Google Trends will show you all searches that contain the terms you entered in any order.)
Note that when you use any of these advanced features – quotation marks, minus signs, or vertical bars – Trends will only display the Search Volume Index graph. The news portion doesn’t support advanced functionality at this time.

7. How is the data scaled?
The data is scaled based on the average search traffic of the term you’ve entered.
There are two modes of scaling – relative and fixed – and the only difference between them is the time frame that’s used to calculate the average. However, fixed scaling is only available as a .csv export. Please note that the ability to see numbers on the graph and to export this data with either mode of scaling are available only after you’ve signed into your Google Account for Trends.
In relative mode, the data is scaled to the average search traffic for your term (represented as 1.0) during the time period you’ve selected. For example, if you entered the term dogs, the graph you’d see would be scaled to the average of all search traffic for dogs from January 2004 to present. But if you chose a specific time frame – say 2006 – the data would then appear relative to the average of all search traffic for dogs in 2006. Then, let’s suppose that you notice a spike in the graph to 3.5; this spike means that traffic is 3.5 times the average for 2006.
In fixed mode, the data is scaled to the average traffic for your term during a fixed point in time (usually January 2004). In our example, 1.0 would be the average traffic of dogs in January 2004. If you chose 2006 as your time frame, you would be comparing data for dogs in 2006 to its data in January 2004. Since the scale basis (1.0) doesn’t change with time, you can look at different time periods, and relate them to each other. (Note: For keywords without a historical record, it may not be possible to establish a fixed scale).

8. Is the News reference volume graph scaled?
No. The graph is for illustrative purposes, and simply shows you the number of times your topic appeared in Google News stories.

9. Is the data normalized?
All results from Google Trends are normalized, which means that we’ve divided the sets of data by a common variable to cancel out the variable’s effect on the data and allow the underlying characteristics of the data sets to be compared. If we didn’t normalize the results, and instead displayed the absolute rankings of cities, they wouldn’t be all that interesting – a densely populated area like New York City would be the top city for many results simply because there are lots of searches from that area.
Remember, Google Trends shows users’ propensity to search for a certain topic on Google on a relative basis. For example, just because a particular region isn’t on the Top Regions list for the term “haircut” doesn’t necessarily mean that people there have decided to stage a mass rebellion against society’s conventions. It could be that people in that region might not use Google to find a barber, use a different term when doing their searches, or simply search for so many other topics unrelated to haircuts, that searches for “haircut” comprise a small portion of the search volume from that region as compared to other regions.

10. Do the numbers on the graph reflect actual search traffic numbers?
No. The numbers you see on the y-axis of the Search Volume Index (which you can see after you’ve signed in to your Google Account) aren’t absolute search traffic numbers. Instead, Trends scales the first term you’ve entered so that its average search traffic in the chosen time period is 1.0; subsequent terms are then scaled relative to the first term. Note that all numbers are relative to total traffic.
Read more about how we scale and normalize the data.

11. I see a number next to my search term at the top of the graph. What does this mean?
The number you see next to your search term corresponds to its total average traffic in the time frame you’ve chosen.
When comparing multiple search terms on a relative scale, the first term you enter will always be 1.0, as subsequent terms are ranked and scaled against this term. For example, you may see: blogs (1.0) and newspapers (0.51). In this case, newspapers has approximately half the searches of blogs.
If you export the data to a .csv file and you’ve selected fixed scaling, 1.0 corresponds to the average traffic for the search term in fixed point of time (usually January 2004), and all numbers are relative to this point. If you chose a time frame of 2007, the number you see for blogs (for example, 5.82) would mean that blogs has had approximately 5.8 times more relative traffic in 2007 than it had in January 2004. Similarly, the the number you see for newspapers (2.05) means that newspapers has about 2 times more traffic in 2007 than blogs had in 2004.
Note that the ratio between these numbers always remains constant and corresponds to how the keywords compare to each other; only the scaling basis (or the meaning of 1.0) changes.
Learn more about scaling.

12. When comparing two or more search terms, I sometimes see results with all zeros. Why?
If you see all zeros for one of your search terms, it could be that the term doesn’t have enough search volume to be reflected on a graph. It’s also possible that the term’s search volume is insignificant compared to the other terms you’ve entered. In those cases, the system will automatically rank your results by whichever term has greater search volume.

13. Is there a way to adjust how the terms are ranked and scaled?
Yes. Use the drop-down menu underneath the graph to change the search term by which all the data will be ranked and scaled (to 1.0). If you have more than one search term, the other terms will be ranked to the first one you’ve entered.

14. How does counting and ranking of the top regions, cities, and languages work, and are they scaled differently?
To rank the top regions, cities, or languages, Google Trends first looks at a sample of all Google searches to determine the areas or languages from which we received the most searches for your first term. Then, for those top cities, Google Trends calculates the ratio of searches for your term coming from each city divided by total Google searches coming from the same city. The city ranking you see on the page and the bar charts alongside each city name both represent this ratio. When cities’ ratios are fairly close together, the corresponding bar graphs will be roughly the same length, and the exact ranking between these cities is less meaningful.
If you export the data to a .csv file, you’ll see numbers for the top regions and cities. These numbers are based on a scale where the top region or city for the search term which you’ve ranked the data by will be 1.0.

15. How is information gathered to determine the regions, cities, and languages?
Google Trends uses IP address information from our server logs to make a best guess about where queries originated. Language information is determined by the language version of the Google site where the search originated.

16. How can I change the time frame, region, or sub-region of the results?
Once you’ve entered your search terms, you can use the drop-down boxes at the top of the results page to restrict your results to a particular time frame or region. The restrictions will affect both the Search Volume Index graph and the News reference volume graph. Please note that News reference volume may not be available for every region.
When you restrict your results to a specific year or multi-year period, each point on the graph will represent a week’s worth of searches. When you restrict the results to a specific month, each point on the graph will represent one day of searches.

17. Is there a way to export the data?
Yes. You can export the data to a .csv file, which can be opened in most spreadsheet applications. Click Export this page to a CSV file at the bottom of the page. You can choose to export the file with relative or fixed scaling. You’ll also see numbers corresponding to the bars under the Regions, Cities, and Languages columns.
The .csv file will also contain data for the top regions, cities, and languages for your search term. Read how this data is counted and ranked.
Along with the search index volume data, the file will include the upper bound of relative standard error for each data point. In your spreadsheet application, every column with search index data will be followed by a column of corresponding relative standard error. This information can be used to calculate the confidence interval for a data point.
Please note that since the news data isn’t scaled, it won’t be included in the file.

18. How does the geographical assignment change from 1/1/2011 affect the data I see?
On July 12, 2011 we rolled out a significant improvement to our geographical assignment. The improvement allows us to provide even better geo-location data for search queries. This update was applied retroactively from January 1, 2011 and may manifest itself in certain queries as a discontinuity in the trend line.

19. When is it okay to use the information I find on Google Trends?
You’re free to use any of the information you find on Google Trends, subject to the Terms of Use. If you choose to use the information, please make sure to appropriately attribute it to Google.

20. This tool makes search information public. What about my personal search data?
You can rest assured your personal search data remains safe and private. Our graphs are based on aggregated data from millions of searches done on Google over time. Moreover, the results Google Trends displays are produced entirely by an automated formula. As an additional measure, Trends only returns results for terms that receive a significant amount of search traffic.