Independent variable

An independent variable is used in statistics to predict or explain a dependent variable.

For example, Age and Gender might be used as independent variables to predict the age of death or life expectancy (dependent variables).

In experimental designs, the independent variables are manipulated by the researcher (e.g., different dosages of a drug). In quasi-experimental and non-experimental designs, the independent variables may be naturally-occurring, non-manipulated variables which are measured and used to predict variations in the dependent variables.

Example

Q: Water temperature is an example of an independent variable, right?

A: Yes and no; Water temperature could be dependent or independent, e.g.,

1. Water temperature (WT) used to predict rates of malaria (WT is the independent variable).
2. Daylight hours used to predict WT (WT is the dependent variable).

See also

• Dependent variable
• Independent variable (Wikipedia)
• Variable