DOE Simplified, 3rd Edition

Glossary

Statistical Symbols

df degrees of freedom

k number of factors in design

i individual datum

n number of observations in sample

p fraction of design (example 2k–p) or probability value (ex. Prob > F)

PI Prediction Interval

r sample correlation coefficient

R2 index of determination

s sample standard deviation

s2 sample variance

t t-value

X independent variable

Y observed response value

Z uncontrolled variable

* multiplication symbol

— (bar) average (e.g., $\overline{Y}$ )

^ (hat) predicted (e.g., $\widehat{Y}$ )

α (alpha) Type I error rate

β (beta) coefficient or Type II error rate

Δ (delta) difference (e.g., ΔY)

σ (sigma) population (true) standard deviation

Σ (capital sigma) mathematical operator to take the sum of a number series

μ (mu) population (true) ...