STAT 22500 Lecture Notes - Lecture 3: Confounding, Blind Experiment, Observational Study

• School: Purdue University
• Department: Statistics
• Course: STAT 22500
• Professor: Tim Reese

Document Summary

Response variable (dependent variable) a variable that measures an outcome or result of a study explanatory variable (independent variable) a variable that attempts to explain or causes changes in the response variable. Lurking variable a variable that has an effect on the response variable but is not part of the study. Confounding variable a variable whose effect on the response variable cannot be separated from the effect of an explanatory variable. Experiment we create differences in the explanatory variable (independent variable) and then examine the results. Observational study we observe differences in the explanatory variable (independent variable) and then notice whether these are related to differences in the response variable. It is important to notice that the difference between an experiment and observational study is with the explanatory variable(s). In an experiment we assign the levels of the explanatory variable and in an observational study we simply observe these differences.