Sociological studies test relationships in which change in one variable causes change in another.
For instance a sociological study might test the effect of ethnicity (independent variable) on income levels (dependent variables). This means that the study will test whether being Caucasian, Asian, Hispanic, African, etc., affect how much or how little a person earns from his or her employment. The result of this investigation can indicate how a change in ethnicity (a variable) creates a change in income (another variable).
