Symbol formats The table below summarizes the correct format of statistical parameters. In many cases, Greek letters are used to indicate the population parameter for a statistic, and corresponding English letters are used to indicate the sample statistic that is an estimate of that population parameter. Symbols should be italicized in all cases where they represent a constant value. Associated subscripts and superscripts are generally not italicized (but see below): Population Parameter Population Parameter Symbol Sample Parameter population size population mean (arithmetic) N sample size sample mean (arithmetic) population mean (geometric) G (mG in Symbol font) population mean (harmonic) H (mH in Symbol font) population median ˜ (“-tilde” created (m in Symbol font) using the Insert menu Object… Microsoft Equation function in Microsoft Office) population variance population standard deviation 2 (s2 in Symbol font) (s in Symbol font) population skewness population kurtosis population correlation 1 (g1 in Symbol font) 2 (g2 in Symbol font) (r in Symbol font) Sample Parameter Symbol n x (created using the Insert menu Object… Microsoft Equation function in Microsoft Office). The word “mean”, as in “mean = 27.2 is also acceptable. sample mean (geometric) xG (created using the Insert menu Object… Microsoft Equation function in Microsoft Office). The abbreviation “GM”, as in “GM = 27.2 is also acceptable. sample mean (harmonic) x H (created using the Insert menu Object… Microsoft Equation function in Microsoft Office) The phrase “harmonic mean”, as in “harmonic mean = 27.2 is also acceptable. sample median xχ (“x-tilde”created using the Insert menu Object… Microsoft Equation function in Microsoft Office). The word “median”, as in “median = 27.2 is also acceptable. sample variance s2 sample standard deviation s standard error of the mean SE or SEM coefficient of variation CV sample skewness g1 sample kurtosis g2 sample correlation r coefficient (Pearson’s) coefficient of determination 2 (r2 in Symbol font) (population) regression line intercept 0 (b0 in Symbol font) regression line slope(s) i (bi in Symbol font, where i = the variable number) regression line variables: y and x(s) coefficient (Pearson’s) coefficient of r2 determination (sample) Regression line intercept b0 (estimated from sample data) Regression line slope(s) bi (where i = the variable estimates from sample number) data) Your call: can be upper or lowercase, italicized or not. Symbols used in statistical tests: Probability should be expressed as P, and “alpha” as (a in Symbol font). Critical values are generally not reported. There should always be a space on either side of any “equals sign” ( = ). The test statistics z, t, chi-squared, and F should be represented as: z (or z) neither subscript is italicized, but the numerical value for or /2 is substituted for the (or /2). Often (n = the sample size) is also included. The P-value may or may not be reported t (or t) neither subscript is italicized, but the numerical value for a or a/2 is substituted. Always report the P value and the degrees of freedom or include the alpha and degrees of freedom in the subscript (e.g., t0.975,35 = the test statistic). Alternatively, report t = the test statistic (df P = the P-value). 2 needs to have the alpha and degrees of freedom reported, as well as the P-value: 2,df = the test statistic (e.g., 2,12). Alternatively, report 2 = the test statistic (df P = the P-value). For F, always report both the numerator and the denominator degrees of freedom (e.g., F2,35 = the test statistic; P = the P-value) or include it in parentheses, e.g., (F(2,35) = the test statistic; P = the P-value). Other symbols of potential value: > greater than ≥ greater than or equal to (option >) >> much greater than < less than ≤ less than or equal to (option <) << much less than = equal to ≠ (option =) not equal to ≈ (option-x) “approximately equal to” (Symbol font) or • (option-8) multiplication sign ÷ (option-/) division sign – (option--) subtraction sign (“m-dash”, wider than – “n-dash”) ∞ (option-5) infinity symbol (, the infinity symbol in Symbol font, is more often used) ° (option-shift-8) degree symbol ‰ (option-shift-R) “parts per thousand” symbol