# Independent Random Variable

An independent random variable is a abstract random variable whose correlational relationship to one or more dependent variables is sought.

**AKA:**Control Variable, Regressor, Manipulated Variable, Explanatory Variable, Exposure Variable.**Context:**- It can (often) be instantiated as a Predictor Feature Function.
- It can range from being a Categorical Independent Random Variable to being an Ordinal Independent Random Variable to being a Continuous Independent Random Variable.
- It must have two or more Independent Variable Levels.
- It can range from being a Between-Subject Independent Variable to being a Within-Subject Independent Variable.

**Counter-Example(s):****See:**Controlled Experiment, Experiment Variable, Explanatory Variable.

## References

### 2015

- (Wikipedia, 2015) ⇒ http://en.wikipedia.org/wiki/covariate Retrieved:2015-7-8.
- In statistics, a
**covariate**is a variable that is possibly predictive of the outcome under study. A covariate may be of direct interest or it may be a confounding or interacting variable.The alternative terms explanatory variable, independent variable, or predictor, are used in a regression analysis. In econometrics, the term "control variable" is usually used instead of "covariate". In a more specific usage, a covariate is a secondary variable that can affect the relationship between the dependent variable and other independent variables of primary interest.

An example is provided by the analysis of trend in sea-level by . Here the dependent variable (and variable of most interest) was the annual mean sea level at a given location for which a series of yearly values were available. The primary independent variable was "time". Use was made of a "covariate" consisting of yearly values of annual mean atmospheric pressure at sea level. The results showed that inclusion of the covariate allowed improved estimates of the trend against time to be obtained, compared to analyses which omitted the covariate.

- In statistics, a

### 2014

- http://en.wikipedia.org/wiki/Dependent_and_independent_variables#Independent_variable
- An independent variable is also known as a "predictor variable", "regressor", "controlled variable", "manipulated variable", "explanatory variable", “exposure variable” (see reliability theory), “risk factor” (see medical statistics), “feature” (in machine learning and pattern recognition) or an "input variable."
^{[1]}^{[2]}"

**Explanatory variable**" is preferred by some authors over "independent variable" when the quantities treated as "independent variables" may not be statistically independent.^{[3]}^{[4]}Independent variable(s) may be of these kinds: continuous variable(s), binary/dichotomous variable(s), nominal categorical variable(s), ordinal categorical variable(s), among others.

- An independent variable is also known as a "predictor variable", "regressor", "controlled variable", "manipulated variable", "explanatory variable", “exposure variable” (see reliability theory), “risk factor” (see medical statistics), “feature” (in machine learning and pattern recognition) or an "input variable."

- ↑ Dodge, Y. (2003)
*The Oxford Dictionary of Statistical Terms*, OUP. ISBN 0-19-920613-9 (entry for "independent variable") - ↑ Dodge, Y. (2003)
*The Oxford Dictionary of Statistical Terms*, OUP. ISBN 0-19-920613-9 (entry for "regression") - ↑ Everitt, B.S. (2002) Cambridge Dictionary of Statistics, CUP. ISBN 0-521-81099-X
- ↑ Dodge, Y. (2003)
*The Oxford Dictionary of Statistical Terms*, OUP. ISBN 0-19-920613-9

### 2011

- http://en.wikipedia.org/wiki/Dependent_and_independent_variables
- … In statistics, the dependent/independent variable terminology is used more widely than just in relation to controlled experiments. For example the data analysis of two jointly varying quantities may involve treating each in turn as the dependent variable and the other as the independent variable. However, for general usage, the pair
**response variable**and**explanatory variable**is preferable as quantities treated as "independent variables" are rarely statistically independent.^{[1]}^{[2]} - Depending on the context, an independent variable is also known as a "predictor variable," "regressor," "controlled variable," "manipulated variable," "explanatory variable," "exposure variable," and/or "input variable."
^{[3]}A dependent variable is also known as a "response variable," "regressand," "measured variable," "observed variable," "responding variable," "explained variable," "outcome variable," "experimental variable," and/or "output variable."^{[4]}

- … In statistics, the dependent/independent variable terminology is used more widely than just in relation to controlled experiments. For example the data analysis of two jointly varying quantities may involve treating each in turn as the dependent variable and the other as the independent variable. However, for general usage, the pair

- ↑ Everitt, B.S. (2002). Cambridge Dictionary of Statistics, CUP. ISBN 0-521-81099-x
- ↑ Dodge, Y. (2003).
*The Oxford Dictionary of Statistical Terms*, OUP. ISBN 0-19-920613-9 - ↑ Dodge, Y. (2003).
*The Oxford Dictionary of Statistical Terms*, OUP. ISBN 0-19-920613-9 (entries for "independent variable" and "regression") - ↑ Dodge, Y. (2003).
*The Oxford Dictionary of Statistical Terms*, OUP. ISBN 0-19-920613-9 (entry for "regression")

### 2009

- http://en.wiktionary.org/wiki/independent_variable
- independent variable (plural independent variables)
- 1. (algebra) In an equation, any variable whose value is not dependent on any other in the equation. In the equation z = x2 + y, x and y are the independent variables.
- 2. (sciences) The variable that is changed in an experiment.

- independent variable (plural independent variables)