***

*

PAGE RETIRED: Click here for the new StatsDirect help system.

*

OR YOU WILL BE REDIRECTED IN 5 SECONDS

*

***

Glossary of symbols and abbreviations

 

y^x

y to the power of x (also seen as y**x or image\STAT0306_wmf.gif)

 

 

^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

analysis of variance

 

 

beta, b

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 image\STAT0307_wmf.gif

 

 

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

 

 

image\STAT0308_wmf.gif

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, image\STAT0309_wmf.gif) - 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 image\STAT0310_wmf.gif

 

 

image\STAT0311_wmf.gif

sum of all (1 to n) x values

 

 

image\STAT0312_wmf.gif

product of all (1 to n) x values (x1 * x2 * x3 etc.)

 

 

VAR

variance (of the mean, image\STAT0313_wmf.gif), greek s² for populations and s² for samples

 

 

vs.

versus

 

 

x

individual value from a population or sample

 

 

image\STAT0314_wmf.gif

x bar (bar symbol above the x denotes mean) is a sample mean (arithmetic mean, image\STAT0315_wmf.gif), see also m

 

 

Z, N

standardized normal deviate (from standard normal distribution)