Editing Level of measurement (section)

==== Same variable may be different scale type depending on context ====
Another issue is that the same variable may be a different scale type depending on how it is measured and on the goals of the analysis. For example, hair color is usually thought of as a nominal variable, since it has no apparent ordering.<ref>{{cite web|url=http://www.ats.ucla.edu/stat/mult_pkg/whatstat/nominal_ordinal_interval.htm|title=What is the difference between categorical, ordinal and interval variables?|work=Institute for Digital Research and Education|publisher=University of California, Los Angeles|archive-url=https://web.archive.org/web/20160125165359/http://www.ats.ucla.edu/stat/mult_pkg/whatstat/nominal_ordinal_interval.htm|access-date=7 February 2016|archive-date=2016-01-25}}</ref> However, it is possible to order colors (including hair colors) in various ways, including by hue; this is known as [[colorimetry]]. Hue is an interval level variable.