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Coefficient Of Concordance
Kendall's ''W'' (also known as Kendall's coefficient of concordance) is a non-parametric statistic for rank correlation. It is a normalization of the statistic of the Friedman test, and can be used for assessing agreement among raters and in particular inter-rater reliability. Kendall's ''W'' ranges from 0 (no agreement) to 1 (complete agreement). Suppose, for instance, that a number of people have been asked to rank a list of political concerns, from the most important to the least important. Kendall's ''W'' can be calculated from these data. If the test statistic ''W'' is 1, then all the survey respondents have been unanimous, and each respondent has assigned the same order to the list of concerns. If ''W'' is 0, then there is no overall trend of agreement among the respondents, and their responses may be regarded as essentially random. Intermediate values of ''W'' indicate a greater or lesser degree of unanimity among the various responses. While tests using the standard Pearso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Non-parametric Statistic
Nonparametric statistics is the branch of statistics that is not based solely on parametrized families of probability distributions (common examples of parameters are the mean and variance). Nonparametric statistics is based on either being distribution-free or having a specified distribution but with the distribution's parameters unspecified. Nonparametric statistics includes both descriptive statistics and statistical inference. Nonparametric tests are often used when the assumptions of parametric tests are violated. Definitions The term "nonparametric statistics" has been imprecisely defined in the following two ways, among others: Applications and purpose Non-parametric methods are widely used for studying populations that take on a ranked order (such as movie reviews receiving one to four stars). The use of non-parametric methods may be necessary when data have a ranking but no clear numerical interpretation, such as when assessing preferences. In terms of levels of me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |