STAT151 Chapter 4: Chapter 4 Done in LaTeX

• School: University of Alberta
• Department: Statistics
• Course: STAT151
• Professor: Alireza Simchi

Document Summary

Data could be obtained in three ways: data that are made available by others, data resulting from an experiment, data collected in an observational study. An experiment to compare two drugs a, b on patients for reducing blood pressure. Treatments: the objects to be compared in a comparison study. The units that react to the various treatments that are applied. Comparison study: the response of each experimental unit to its treatment is observed. An experiment is the process of subjecting experimental units to treatments and observing their response. Confounding variable (lurking variable): a variable, usually unobserved, that in uences the association between the variables of primary interest. The presence of confounding variable makes it hard to establish the outcome as being a direct consequence of the variable of primary interest. Suppose we want to determine the e ect of a new plant stimulator on the growth of a commercially produced ower.