The two main types of variables are:
- Independent variables : These are variables that are manipulated or controlled in an experiment to observe their effect on another variable. They stand alone and are not affected by other variables in the study. For example, the amount of time spent revising for a test or the IQ score of students are independent variables that might affect test performance
- Dependent variables : These variables depend on or are influenced by the independent variables. They are the outcomes or responses measured in an experiment. For instance, the test scores students achieve depend on factors like revision time and intelligence, making test scores a dependent variable
Additionally, variables can also be classified by the type of data they represent:
- Quantitative variables : These represent numerical amounts and can be discrete (countable values) or continuous (measurable values without gaps)
- Categorical variables : These represent groupings or categories and can be nominal (no order), ordinal (ordered), or binary (two categories)
However, the primary distinction in many contexts, especially experimental research, is between independent and dependent variables.
