Interesting website: Distinguishing Association from Causation: A Backgrounder for Journalists (Kathleen Meister). This 24 page report, published on October 29, 2007, by the American Council on Science and Health, argues that randomized trials, if they can be conducted, provide strong evidence for a causal effect. In contrast, animal and in vitro experiments do not provide strong evidence for a causal relationship but rather are useful for establishing biological mechanisms. Observational studies can sometimes establish a causal relationship. The key things to look for are temporality of the relationship, strength of the relationship, a dose-response relationship, consistency across varied conditions, and biological plausibility. The description of this website was written by Steve Simon on 2007-11-16, edited by Steve Simon, and was last modified on 2008-06-21. This website was last verified on 2007-11-16. Send feedback to ssimon at cmh dot edu or click on the email link at the top of the page. Category: Critical appraisal, Category: Interesting websites. URL: www.acsh.org/publications/pubID.1629/pub_detail.asp