Glossary of Symbols and Abbreviations


y^x y to the power of x (also seen as y**x or yx)
^Key Ctrl + another Key
/ divided by (see calculator for operator precedence)
* multiplied by (see calculator for operator precedence)
abs(x), |x| absolute value of x without regard to sign
alpha, α significance level of a hypothesis test (also type I error rate). 1-a is the level of the confidence interval
ANOVA analysis of variance
beta, β type II error rate (1-power)
CI confidence interval, see confidence intervals
df degrees of freedom
e base of natural logarithms (2.718281...)
k! factorial , in simplest terms factorial of k is the product of all integers from 1 to k, with 0! defined as 1, a fuller definition relates factorial to the gamma function as gamma (k+1) which enables the calculation of fractional factorials
ln(x) natural (base e) logarithm of x, the natural logarithm of x is the value of y such that x is equal to the e constant raised to the power of y, remember that ln(1) = 0, ln(0) = minus infinity and ln(a/b)=ln(a)-ln(b), see also transformations
MS mean square
μ mean of a population - see also
n sample size (population sized is usually referred to as N)
P probability of the data (or more extreme data) arising by chance, see P values
p proportion of a sample with a given characteristic
q hat, the hat symbol above the q means "estimate of"
r Pearson's product moment correlation coefficient
SD standard deviation (of a sample, ) - a measure of variability around the mean - Greek lower case sigma (σ) is used for population standard deviation.
SE standard error (of sample mean, ) - a measure of uncertainty of the estimate of a statistic (e.g. sample mean) and used to derive confidence intervals for the population value of the statistic
sqr(x) square root of x, or
sum of all (1 to n) x values
product of all (1 to n) x values (x1 * x2 * x3 etc.)
VAR variance (of the mean, ), greek σ² for populations and s² for samples
vs. versus
x individual value from a population or sample
x bar (bar symbol above the x denotes mean) is a sample mean (arithmetic mean, ), see also μ
z, Φ standardized normal deviate (from standard normal distribution)



Copyright © 2000-2016 StatsDirect Limited, all rights reserved. Download a free trial here.