y^x
y to the power of x (also seen as y**x or 
)
^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, a
significance level of a hypothesis test (also type I error rate). 1-a is the level of the confidence interval
ANOVA
beta, b
CI
confidence interval, see confidence intervals
df
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, s = SQR(VAR)) - a measure of variability around the mean - Greek lower case sigma (s) 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, equivalent to 
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 s² 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 m
Z, N
standardized normal deviate (from standard normal distribution)