I first heard about Google Flu Trends a few years back when the tool first came out. Basically Google looks at all the people all over the world searching for the term ‘flu’ using its search engine (and probably some related terms like ‘influenza’). Because it can tell where users are and can see in real time when there’s a sudden spike in the number of people searching ‘flu’, Google can tell when and where there’s a flu outbreak.
The screenshot above shows data for the whole US. There’s a timeline showing the incidence of flu from month to month for each year since 2005-2006, and you can toggle different years on and off. If you hover over any state on the interactive map, a little info window pops up that gives you the basic information on the current flu incidence in that state. The window follows your cursor and changes as you move from state to state, so you never have to click to see anything. If you do want more information on a specific state though, you can click on it, and the graph at the top will change to only show data for that one state. I really like how the map and the chart complement each other. Like most of Google’s products, it’s clean, simple and intuitive.
You can also click to switch from looking at states to major cities. If you hover over a metro region, a zoomed-in map pops up to show the different cities within the region.
I think this is a great model for any of us looking at state-by-state data or looking at trends over time.