Title: Interactions between Health Searchers and Search Engines,
Abstract: The Web is an important resource for understanding and diagnosing medical
conditions. Based on exposure to online content, people may develop undue
health concerns, believing that common and benign symptoms are explained by
serious illnesses. In this paper, we investigate potential strategies to mine
queries and searcher histories for clues that could help search engines choose
the most appropriate information to present in response to exploratory medical
queries. To do this, we performed a longitudinal study of health search
behavior using the logs of a popular search engine. We found that query
variations which might appear innocuous (e.g. "bad headache" vs "severe
headache") may hold valuable information about the searcher which could be used
by search engines to improve performance. Furthermore, we investigated how
medically concerned users respond differently to search engine result pages
(SERPs) and find that their disposition for clicking on concerning pages is
pronounced, potentially leading to a self-reinforcement of concern. Finally, we
studied to which degree variations in the SERP impact future search and
real-world health-seeking behavior and obtained some surprising results (e.g.,
viewing concerning pages may lead to a short-term reduction of real-world
health seeking).