handout_2_1 - Chapter 2 Looking at Data we often care about the relationship between two variables to study the relationship we measure both variables

Chapter 2- Looking at Data •we often care about the relationship between two variables •to study the relationship, we measure both variables on the same individuals Two variables measured on the same individuals are associated if some values of one variable tend to occur more often with some values of the second variable than with other values of that variable. EX- taller people tend to be heavier EX- people who smoke a lot of cigarettes tend not to live as long as those who do not response variable - measures an outcome of a study explanatory variable - explains or causes change in the response variables independent variables - explanatory variables dependent variables - response variables Many explanatory-response variables do not involve direct causation. EX- SAT scores predict future college grades. SAT scores, however, don’t have a causal impact on college gpa.