Data set: Difference between revisions

Revision as of 08:13, 28 June 2022

Revision as of 10:56, 18 July 2022

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==Properties==

Several characteristics define a data set's structure and properties. These include the number and types of the attributes or variables, and various [[statistical measure]]s applicable to them, such as [[standard deviation]] and [[kurtosis]].<ref>{{Cite book |url=https://books.google.com/books?id=uTzeRZFmaBgC&pg=PA100 |title=Principles of data mining and knowledge discovery |author=Jan M. Żytkow, Jan Rauch |isbn=978-3-540-66490-1 |year=1999}}</ref>

The values may be numbers, such as [[real number]]s or [[integer]]s, for example representing a person's height in centimeters, but may also be [[nominal data]] (i.e., not consisting of [[Number|numerical]] values), for example representing a person's ethnicity. More generally, values may be of any of the kinds described as a [[level of measurement]]. For each variable, the values are normally all of the same kind. However, there may also be ''[[missing values]]'', which must be indicated in some way.