Nominal Scale 1 : Classification into unordered qualitative categories; e.g., race, religion, and country of birth as measurements of individual attributes are purely nominal scales, as there is no inherent order to their categories
Cornell University, Department Neurobiology and Behavior, Course: Clinical Neurobiology, Glossary of Epidemiological Terms, New York, USA 2012. https://courses.cit.cornell.edu/bionb4280/Epidemio logy%20Terms.pdf, (Dzstr Prep/ Epid - Amer) {1004}