explanatory variable
affects the value of the response variable
response variable
is affected by changes in the value of the explanatory variable
confounding
when the effects of 2 or more explanatory variables are not separated, so any relation between the explanatory variable and response variable may be due to some other variable not accounted for in the study
lurking variable
an explanatory variable that was not considered in a study but affects the value of the response variable in the study
cross sectional study
collect info at a specific point in time, or a very short period of time
case control study
look back in time and individuals with a certain characteristic are matched with those that do not have that characteristic (more beneficial study)
observational study
measures the value of the response variable without attempting to influence the value of either the response or explanatory variables. The researcher observes the behavior of the individuals in the study without trying to influence the outcome of the stud
experiment
the researcher assigns the individuals in a study to a certain group, intentionally changes the values of an explanatory variable and then records the value of the response variable for each group