Finite Unordered Set

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A Finite Unordered Set is an ordered set that is a finite set.



  • (Wikipedia, 2015) ⇒ Retrieved:2015-6-1.
    • The nominal type differentiates between items or subjects based only on their names or (meta-)categories and other qualitative classifications they belong to; thus dichotomous data involves the construction of classifications as well as the classification of items. Discovery of an exception to a classification can be viewed as progress. Numbers may be used to represent the variables but the numbers do not have numerical value or relationship.

      Examples of these classifications include gender, nationality, ethnicity, language, genre, style, biological species, and form.[1][2] In a university one could also use hall of affiliation as an example. Other concrete examples are

    • Nominal scales were often called qualitative scales, and measurements made on qualitative scales were called qualitative data. However, the rise of qualitative research has made this usage confusing.
  1. Nominal measures are based on sets and depend on categories, ala Aristotle. accessdate=2014-08-25
  2. "Invariably one came up against fundamental physical limits to the accuracy of measurement. … The art of physical measurement seemed to be a matter of compromise, of choosing between reciprocally related uncertainties. … Multiplying together the conjugate pairs of uncertainty limits mentioned, however, I found that they formed invariant products of not one but two distinct kinds. … The first group of limits were calculable a priori from a specification of the instrument. The second group could be calculated only a posteriori from a specification of what was done with the instrument. … In the first case each unit [of information] would add one additional dimension (conceptual category), whereas in the second each unit would add one additional atomic fact.", – pp. 1–4: MacKay, Donald M. (1969), Information, Mechanism, and Meaning, Cambridge, MA: MIT Press, ISBN 0-262-63-032-X