Which scale of measurement assigns numbers to objects solely for identification?

The nominal scale of measurement is designed specifically for categorizing objects or individuals without implying any quantitative value or order. In this scale, numbers serve only as labels or identifiers for different categories. For example, in a study where individuals are categorized by their favorite colors, different colors can be assigned different numbers (e.g., 1 for red, 2 for blue, etc.) purely for identification purposes.

This means that the numbers have no mathematical meaning or rank; they simply differentiate one category from another. As such, the nominal scale is often used for demographic data like gender or ethnicity, where the categories are distinct, but there is no inherent order or value attached to them.

The other scales of measurement, such as ordinal, interval, and ratio, imply levels of ranking or quantification that go beyond mere identification. The ordinal scale introduces a meaningful order among categories, the interval scale not only orders the data but also specifies equal intervals between values, and the ratio scale includes a true zero point allowing for the comparison of absolute magnitudes. Thus, while these other scales provide additional information beyond simple identification, the nominal scale focuses exclusively on distinguishing between different categories.