Ordinalasteikkoon

Ordinalasteikkoon is a Finnish term that translates to "ordinal scale" or "ordinal scale of measurement." It refers to a level of measurement in statistics where data can be ranked or ordered, but the differences between the ranks are not necessarily equal or quantifiable. This means that while we know if one observation is greater than another, we cannot say by how much.

In an ordinal scale, categories have a meaningful order. For example, survey responses like "poor," "fair," "good," and "excellent" represent an ordinal scale. We know that "excellent" is better than "good," and "good" is better than "fair," but the perceived difference in quality between "fair" and "good" might not be the same as the difference between "good" and "excellent." Other examples include rankings in a competition (1st, 2nd, 3rd place) or levels of agreement (strongly disagree, disagree, neutral, agree, strongly agree).

Statistical analysis methods suitable for ordinal data include non-parametric tests such as the Mann-Whitney U test, Wilcoxon signed-rank test, and Spearman's rank correlation. These methods respect the ordered nature of the data without assuming equal intervals. Operations like addition or subtraction are generally not appropriate for ordinal data.