A variable where you can assign a numerical value or score, such as age or IQ score
A third variable that could potentially influence the dependent variable in addition to the independent variable
A qualitative variable with only two categories, often coded as zero and one (e.g., yes/no)
The variable that is manipulated by the researcher to observe its effect on another variable
The variable that is measured to see if it is affected by the independent variable; it is the outcome
A variable that categorises observations using names or labels, like gender or marital status
A quantitative variable where values can only be whole numbers (no decimals), such as the number of children
