Link Search Menu Expand Document

Google Symptom Surveys

  • Source name: google-survey
  • Number of data revisions since 19 May 2020: 0
  • Date of last change: Never
  • Available for: county, hrr, msa, state (see geography coding docs)

Data source based on Google-run symptom surveys, through publisher websites, their Opinions Reward app, and similar applications. Respondents can opt to skip the survey and complete a different one if they prefer not to answer. The survey is just one question long, and asks “Do you know someone in your community who is sick (fever, along with cough, or shortness of breath, or difficulty breathing) right now?” Using this survey data, we estimate the percentage of people in a given location, on a given day, that know somebody who has a COVID-like illness. This estimates a similar quantity to the *_cmnty_cli signals from the Symptom Surveys (fb-survey) source, but using a different survey population and recruitment method.

The survey sampled from all counties with greater than 100,000 population, along with a separate random sample from each state. This means that the megacounties (discussed in the COVIDcast API documentation) are always the counties with populations smaller than 100,000, and megacounty estimates are created by combining the state-level survey with the observed county surveys.

These surveys were run daily until May 15, 2020. After that date, new national data will not be collected regularly, although the surveys may be deployed in specific geographical areas as needed to support forecasting efforts.

Signal Description
raw_cli Estimated percentage of people who know someone in their community with COVID-like illness
smoothed_cli Estimated percentage of people who know someone in their community with COVID-like illness, smoothed in time