STAT 3090- Final Exam Guide - Comprehensive Notes for the exam ( 35 pages long!)
28 Mar 2018
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Chapter 2 data, reality and problem solving. For years the tobacco industry argued that the only way to answer this question was to conduct a controlled experiment in which the variable of interest, smoking, was the only difference between an experimental group and a control group. Since it is unethical to expose individuals to a potentially harmful treatment, no such studies were able to be conducted. We could argue that the whole experiment could be avoided by just comparing the cancer levels among individuals of a certain age who smoke to those of the same age who do not smoke. More complex statistical methods are required to draw associations in these types of situations. Observational studies come about by measuring what is . With observational studies cause and effect cannot be determined but an association may be present. There is no attempt to manipulate the subjects being studied.
