For statistical purposes, it usually is not important to differentiate between which two scales of measurement?

For statistical purposes, it usually is not important to differentiate between which two scales of measurement?

• A. Nominal and ordinal
• B. Ordinal and interval
• C. Interval and ratio
• D. Nominal and interval

Answer: (C)

Distances between measurements are meaningful on both interval and ratio scales, so the arithmetic that underpins many statistical procedures relies on equal spacing rather than the presence of a true zero. Because of that, you can compute and compare means, standard deviations, correlations, and run many parametric tests (like t-tests and regressions) on either interval or ratio data without needing to distinguish them for those analyses. The key distinction that ratio scales have a true zero and allow meaningful ratios, while interval scales do not, matters for interpreting ratios but not for the basic operations and many results that rely on differences and averages. That’s why, in many statistical contexts, interval and ratio are treated as functionally similar for purposes of analysis. The other scale pairings involve categorical labeling or ordered but uneven intervals, which restrict certain analyses in ways that require keeping their differences apart.

Distances between measurements are meaningful on both interval and ratio scales, so the arithmetic that underpins many statistical procedures relies on equal spacing rather than the presence of a true zero. Because of that, you can compute and compare means, standard deviations, correlations, and run many parametric tests (like t-tests and regressions) on either interval or ratio data without needing to distinguish them for those analyses. The key distinction that ratio scales have a true zero and allow meaningful ratios, while interval scales do not, matters for interpreting ratios but not for the basic operations and many results that rely on differences and averages. That’s why, in many statistical contexts, interval and ratio are treated as functionally similar for purposes of analysis. The other scale pairings involve categorical labeling or ordered but uneven intervals, which restrict certain analyses in ways that require keeping their differences apart.