Statistical Sciences 1023A/B Lecture Notes - Lecture 4: Confidence Interval, Nicotine, Sampling Frame
30 Jan 2017
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Document Summary
Lecture 4 - how to get a good sample. A subgroup of a large population is questioned on a set of topics. No intervention or manipulation of the respondents, simply asked t answer some questions. Measures the effect of manipulating the environment in some way. Randomized experiment - manipulation is assigned to participants on a random basis. Randomization helps to make the groups approximately equal in all respects except for the explanatory variable. Cannot assume the explanatory variable is the only one responsible for any observed differences in the response variable. Case-control study attempts to include an appropriate control group. Sometimes results more readily extend to the real world in an experiment-no artificial manipulation (when people participate in experiment, they know being tested so it"s not necessarily real) Quantitative review of a collection of studies all done on a similar topic. Combining information can lead to emergence of patterns or effects not readily seen in the individual studies.
