Variables

A hypothesis poses a relationship between two or more aspects of   social relationships.  These aspects are called variables. A variable is a measurable trait or characteristic that is subject to change under different conditions.  Income, gender, occupation, and religion are variables.   Variables may be independent or dependent.

Independent Variables: Independent variables in a hypothesis are those that influence or cause changes in another variable.  In other words, an independent variable is something that is chosen by the researcher to cause a change in another variable.

Dependent Variables: The dependent variables are those variables are believed to be influenced by the independent variable (Schaefer and Lamm 1992:38).

 

Example: Independent and Dependent Variables Higher levels of education produce greater earnings. Education is the independent variable (it causes the change in income levels). Income level is the dependent variable. The income an individual earns "depends" or is determined by the influence of education.

Correlation

One of the most common research mistakes is to assume that a high correlation between two variables means that one variable (independent) causes some change in another variable (dependent).

A correlation exists when a change in one variable coincides with a change in another variable. The fact that a correlation exists means that the two variables are associated statistically with one another.  However, the mere fact that associations exist, does not necessarily mean that a change in one variable causes a change in another variable. Correlations are an indication that causality may be present.   They do not necessarily indicate causation (Schaefer and Lamm 1992: 38).