Recognizing commonly used statistical symbols

In statistics, you will come across many symbols. On this page you will find the most commonly used statistical symbols in alphabetical order with their name and meaning for a quick reference.

Commonly used statistical symbols

Commonly used greek symbols
Commonly used latin symbols
Commonly used mathematical symbols

Commonly used greek symbols

Sign	Description	Meaning in statistics
\[\huge{\alpha}\]	Alpha	Chance of type I error
\[\huge\beta\]	Beta	Chance of type II error
\[\huge\beta_i\]	Beta of i	Standardised regression coëfficiënt
\[\huge\epsilon\]	Epsilon	Error
\[\huge\eta^2\]	Eta squared	Measurement of effect size
\[\huge\mu\]	Mu	Mean of scores of population
\[\huge\rho\]	Rho	Correlation in population
\[\huge\sigma\]	Sigma	Standard deviation
\[\huge\sigma^2\]	Sigma squared	Variance of population
\[\huge\sigma_x\]		Standard error
\[\huge\tau\]	Kendall’s Tau	A non-parametric correlation coefficient
\[\huge\varphi\]	Phi	Association between two categorical variables
\[\huge \chi^2\]	Chi-square	Association between two categorical variables
\[\huge\omega^2\]	Omega squared	Measurement of effect size

Commonly used latin symbols

Sign	Meaning in statistics
\[\huge b_i\]	Regression coefficient
\[\huge df\]	Degrees of freedom
\[\huge e_i\]	Error associated with variable i
\[\huge F\]	F-statistic
\[\huge H\]	Kruskall-Wallis test statistic
\[\huge k\]	Number of levels of variables
\[\huge ln\]	Natural logarithm
\[\huge MS\]	Mean squared error
\[\huge N, n, n_1\]	Size of sample of population
\[\huge P\]	Probablity
\[\huge r\]	Pearson’s correlationcoefficient
\[\huge r_s\]	Spearman’s rank correlationcoefficient
\[\huge r_b\]	Biserial correlationcoefficient
\[\huge r\]	Multiple correlationcoefficient
\[\huge R^2\]	Determination coefficient
\[\huge s\]	Standard deviation of sample of population
\[\huge s^2\]	Variance of sample of population
\[\huge SS\]	Sum of squares
\[\huge SSA\]	Sum of squares of variable A
\[\huge SS_M\]	Model of sum of squares
\[\huge SS_R\]	Rest sum of squares
\[\huge SST\]	Total sum of squares
\[\huge t\]	Test statistic for t-test
\[\huge t\]	Test statistic for Wilcoxon’s matched-pairs signed-rank test
\[\huge U\]	Test statistic for Mann-Whitney test
\[\huge W_s\]	Test statistic for Wilcoxon’s rank-sum test
\[\huge\bar{x}\]	Mean of sample scores
\[\huge z\]	Point of data expressed in units of standard deviation

Commonly used mathematical symbols

Sign	Description	Meaning in statistics
\[\huge\bar{\small[value]}\]	Bar notation	Mean of: [value], or everything directly below the bar sign
\[\huge\hat{\small[value]}\]	Hat operator notation	Estimator (or predicted value of a sample) of: [value], or everything directly below the hat operator sign
\[\LARGE\prod \small[value]\]	Product notation	Multiplying of: [value], or everything directly after the product sign
\[\LARGE\sum \small[value]\]	Sigma notation	Summification of: [value], or everything directly after the sigma sign
\[\huge\sqrt{\small[value]}\]	Square root notation	Square root of: [value], or everything directly after the square root sign