Survey or questionnaire – what's the difference? In short: the survey is the whole project, the questionnaire is the tool with the questions. We show you clearly how the two connect, when to use which term and what to watch out for in practice.
With an absolute scale the unit is fixed, so a headcount stays a headcount and nothing converts. Find out how to recognise it and which calculations its values will support.
One salary is twice another, but 20°C is never twice as warm as 10°C. The difference is the zero point, and that is what a ratio scale brings to your data.
With an interval scale the distances are equal and the starting point is arbitrary. Find out what that lets you calculate and how it really differs from a ratio scale.
A cardinal scale or metric scale (English: "metric scale") refers to scale levels that, in contrast to nominal or ordinal scales, have a defined metric or numerical distance between two variables (e.g., 5°C between 15 and 20°C in temperature measurement).
The ordinal scale (English: "ordinal scale" = ranking scale) is used to place objects or characteristics in a logical ranking order (greater than, less than) with respect to a specific property.
The nominal scale (engl. "nominal scale" or "categorical scale") is the lowest scaling for measuring qualitative characteristics (gender, marital status, hair color).
The rating scale (English "rating" = evaluation or assessment) is suitable for oral or written statements such as in online surveys to record respondents' personal assessments in gradations.
Objectivity (= intersubjective comparability) means that knowledge gained must be verifiable and comprehensible independent of researchers' subjective attitudes.