STAB22H3 Lecture Notes - Lecture 15: Categorical Variable, Framingham Heart Study, Dependent And Independent Variables

• School: UTSC
• Department: Statistics
• Course: STAB22H3
• Professor: Caren Hasler

Document Summary

Xi experiments and observational studies (p. 318: observational study vs experiment. An observational study observes individuals and measures variables of interest but does not attempt to influence the response. Most o(cid:468) (cid:623)hat (cid:623)e kno(cid:623) a(cid:427)out heart disease (cid:428)ome (cid:468)rom this stud(cid:629) It"s (cid:428)alled an o(cid:427)ser(cid:622)ational stud(cid:629) (cid:427)e(cid:428)ause the resear(cid:428)hers o(cid:427)ser(cid:622)e. An experiment imposes a treatment on individuals in order to observe their response. This is important (cid:427)e(cid:428)ause (cid:623)e (cid:623)ant to understand the (cid:428)ausal relationship: experiments are the gold standard for causal inference. Observational studies are valuable for discovering trends and possible relationships. However, it is not possible for observational studies to demonstrate a causal relationship. When our goal is to understand the cause and effect, experiments are the only source of fully convincing data. We look at a bunch of people, find out if they exercise and how much, and ask them to rate their insomnia. Suppose that the people who exercise more suffer less from insomnia.