central tendency (measures of)
central tendency (measures of) A statistical term applied to the central value in a frequency distribution—commonly referred to as the average. Depending on the level of measurement of the variable (nominal, ordinal, interval, or ratio), and the shape of the distribution (normal or otherwise), various measures of central tendency may be calculated. The mean is the most wellknown, and is obtained by adding together all the individual values in a set of measurements, then dividing the sum by the total number of cases in the set—to give the average age, height, temperature, or whatever. However, if a particular distribution is highly skewed (that is, if there are several numbers of extreme value at one or other end of the series), then it may make more sense to calculate the median. The median is literally the middle value in a series of numbers, and may be used in place of the mean when, for example, average income is calculated, since the distribution of income is generally highly skewed. The third measure of central tendency, the mode, is used to describe the most frequently occurring category of a nonnumeric variable (for example voting intention). It is less frequently employed than the mean or median.
Any elementary statistical textbook will supply formulae for the calculation of measures of central tendency. The following examples may help to illustrate the principles outlined above. If, for example, a poll of voters in a small town suggests that 40 per cent will vote Republican, 35 per cent will vote Democrat, while 25 per cent will not vote at all, then we may say that the typical voter among these townspeople is a Republican. This is the category which has the largest representation—the mode. (A distribution with two modal categories is termed bimodal.) By comparison, the median value in a series is the middle case; or, more precisely, the point which neither exceeds nor is exceeded by more than 50 per cent of the total observations. For example, a number of students might be tested in an examination and receive the following grades: Joan—B, Bill—C, James—D, Brett—F, Joyce—F. In this distribution, the middle case is James, since he has two students ranking above and two below him. The median mark is therefore D. The mean is the measurement of central tendency most people have in mind when they talk about ‘the average’. For example, we may record the number of times a particular university professor at his or her desk is interrupted by telephone calls each day for a week, and obtain the following data: Monday = 4, Tuesday = 6, Wednesday = 4, Thursday = 4, Friday = 2, Saturday = 4. The average number of interruptions per day is therefore 24 (total number of scores in the set) divided by 6 (the number of cases)—giving a mean of 4 calls each day. See also SKEWNESS.
Cite this article
Pick a style below, and copy the text for your bibliography.

MLA

Chicago

APA
"central tendency (measures of)." A Dictionary of Sociology. . Encyclopedia.com. 15 Oct. 2018 <http://www.encyclopedia.com>.
"central tendency (measures of)." A Dictionary of Sociology. . Encyclopedia.com. (October 15, 2018). http://www.encyclopedia.com/socialsciences/dictionariesthesaurusespicturesandpressreleases/centraltendencymeasures
"central tendency (measures of)." A Dictionary of Sociology. . Retrieved October 15, 2018 from Encyclopedia.com: http://www.encyclopedia.com/socialsciences/dictionariesthesaurusespicturesandpressreleases/centraltendencymeasures
Citation styles
Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).
Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.
Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the mostrecent information available at these sites:
Modern Language Association
The Chicago Manual of Style
http://www.chicagomanualofstyle.org/tools_citationguide.html
American Psychological Association
Notes:
 Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
 In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.