Nominal scale labelling – UGC NET Question

A nominal scale classifies observations into distinct categories that are qualitatively different but have no inherent ranking or order, such as gender, blood group or department name. The numbers or labels assigned to categories serve only as identifiers and cannot be meaningfully ordered or compared using greater-than or less-than relations. Because the stem emphasises labelling categories without implying order, it is describing a nominal scale.

Option A:
Nominal scales allow researchers to count frequencies of cases in each category and to examine mode or use chi-square tests, but arithmetic operations like addition or subtraction on the codes are meaningless. They represent “names” rather than quantities. This property matches the stem’s description of simple labelling, confirming nominal as the correct answer.

Option B:
An ordinal scale not only classifies cases but also ranks them, such as in levels of agreement or ranks in a competition. Since ordinal data do imply order among categories, ordinal does not fit the stem, which states there is no implied order.

Option C:
Interval scales have equal intervals between adjacent values and allow meaningful addition and subtraction, but they lack a true zero point; temperature in Celsius is a common example. These features go beyond mere labelling, so interval scale does not match the simple categorical description in the question.

Option D:
Ratio scales possess all the characteristics of interval scales plus a true zero, enabling meaningful ratio comparisons, such as twice as much or half as much. They involve quantitative measurements, not just labels. Consequently, ratio is not the correct completion for a scale that only labels categories without order.