Confirmation bias
White and Horvitz conducted a survey of over 500 people that confirmed the prevalence of web-induced medical anxieties. The survey noted that a significant portion of subjects considered the ranking of a list of results on a medical query as linked to the likelihood of relevant disorders. They point out the potential importance of findings drawn from the psychology of judgment in their work. In particular, they point out that previously studied "biases of judgment" play a role in cyberchondria. The authors highlighted the potential biases of availability (the recency and density of exposure of someone to events raises the assessed likelihood of the events) and base-rate neglect (people often do not properly consider the low prior probability of events occurring) as influencing both search engines and then people searching the web. Confirmation bias, a tendency for people to confirm their preconceptions or hypotheses, may also contribute to cyberchondria.