Two types of variables are of interest in research:

• Discrete variables are those which are simply there or not there (eg. computerisation versus non-computerisation) or of one kind or another (eg, gender). The measurement of discrete variables involves the measurement of different categories which are mutually exclusive. These are also called nameable variables.

• Continuous variables are those that are measured in terms of degree or level (eg, height, age, etc). These sort of variables receive a ranking along a continuum. These variables are also called measurable variables.
  [Adapted from Punch 1998:121]