A variable that categorises observations using names or labels, like gender or marital status

A qualitative variable with only two categories, often coded as zero and one (e.g., yes/no)

A quantitative variable where values can only be whole numbers (no decimals), such as the number of children

The variable that is manipulated by the researcher to observe its effect on another variable

A third variable that could potentially influence the dependent variable in addition to the independent variable

A variable where you can assign a numerical value or score, such as age or IQ score

The variable that is measured to see if it is affected by the independent variable; it is the outcome