Why Google Flu doesn’t accurately predict the flu

  • people are changing their search terms (maybe getting better)
  • searching the flu isn’t actually indicative of the flu
    • having more or less publicity influences searches
    • maybe people are differentiating from the cold
  • we’re not exactly sure how they built their model or if they are changing
  • are they testing and updating their model?
  • Google is changing and now influences your searches
  • CDC has data on real occurances
  • doctor / hospital visit where the flu is noted / tested for
    • 10 regions - multiple locations per region - 300 clinical labs
    • also people who died
  • Google has information on how much people are wondering about the flu
  • knowledge of vaccines and herd immunity (CDC has records)

How predictions are made from the data

  • not sure about google (other than correlated search terms)
  • CDC makes predictions based on actual medical data and trends
    • already 90% accurate

Search terms that correlate

  • just because a term is correlated doesn’t mean they are related
  • things influencing the flu are different than things influencing searches