Independent and dependent variables
When we conduct a linguistic research, we usually work with a number of variables some of which are independent and some are dependent. This post defines these two types of variables.
An independent variable is what is given (e.g. age, sex, social class, geographical location, occupation), the “input”.
An dependent variable is what results from this set of independent variables (e.g. pronunciation of the phoneme [r], use of a particular dialect, use of a particular sociolect).
Depending on the set up of a study one and the same variable (e.g. the use of slang) may be either independent or dependent. Therefore, a variable taken out of the context of a study is neither independent nor dependent in itself. It becomes such only within a given context. You can find a good example of independent and dependent variables within their context in “Social stratification of English” post.