Breaking down the question

Three tasks are embedded here. Define a variable, classify its types, and elaborate — meaning illustrate each type with an example. This is a methods question, so precision of terminology matters more than rhetoric. The examiner wants command over the building blocks of quantitative enquiry.

How to approach it

  • Begin with a tight definition of a variable as a measurable concept that varies.
  • Distinguish the major classificatory schemes rather than heaping types together.
  • For each type, give a one-line sociological example.
  • Reference Lazarsfeld on operationalising concepts to show conceptual depth.
  • Keep the elaboration crisp — this is a 150-word answer, not an essay.

Model answer

A variable is any concept or characteristic in social research that can take different values across cases — for instance, income, education, caste or attitude. It is the operationalised form of a concept, allowing the abstract to be measured and compared. Paul Lazarsfeld stressed this move from concept to measurable indicator.

Variables may be classified in several ways:

  1. Independent variable — the presumed cause, manipulated or observed to explain change, such as level of education.
  2. Dependent variable — the presumed effect, such as occupational status.
  3. Intervening variable — a factor that mediates the relationship between the other two, for example social networks linking education to jobs.
  4. Control variable — held constant to isolate a relationship, such as holding gender fixed.

By level of measurement, variables are also nominal, ordinal, interval or ratio. Durkheim's use of social integration as an explanatory variable in Suicide remains the classic illustration.

For definitions and worked examples, see variables, sampling, reliability and validity.

Examiner's perspective

The examiner rewards clean definitions and correctly paired examples — muddling independent and dependent variables is the commonest slip. Mentioning levels of measurement signals wider methodological literacy. A short, well-organised classification with one apt illustration per type scores better than a vague, discursive account.