Correlation coefficient

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Correlation coefficient may refer to:

  • Pearson product-moment correlation coefficient, also known as r, R, or Pearson's r, a measure of the strength and direction of the linear relationship between two variables that is defined as the (sample) covariance of the variables divided by the product of their (sample) standard deviations.
  • Intraclass correlation, a descriptive statistic that can be used when quantitative measurements are made on units that are organized into groups; describes how strongly units in the same group resemble each other.
  • Rank correlation, the study of relationships between rankings of different variables or different rankings of the same variable

Related concepts:

  • Correlation and dependence, a broad class of statistical relationships between two or more random variables or observed data values
  • Goodness of fit, any of several measures that measure how well a statistical model fits observations by summarizing the discrepancy between observed values and the values expected under the model in question
  • Coefficient of determination, a measure of the proportion of variability in a data set that is accounted for by a statistical model; often called R2; equal in a single-variable linear regression to the square of Pearson's product-moment correlation coefficient.