Key terms and symbols

absolute decisions

agreement coefficient (po)

alpha

chi-square (_2)

confidence interval (CI)

consistency

correlation

correlation coefficient

covary

CRT dependability

decision study (D study)

dependability

directional decision

domain-score dependability

equivalent forms reliability

error

estimated variance component ( )

facet

generalizability coefficients (E__)

generalizability study (G study)

generalizability theory (G theory)

infit

item response theory

internal consistency reliability

invariance of item parameters

invariance of ability estimates

kappa (k)

K-R20 coefficient

K-R21 coefficient

Livingston’s statistic, or k2(XT)

local independence

model to data fit

non-directional decision

NRT reliability

observed score

outfit

outliers

phi, or F

phi(lambda), or F(l)

pchance

relative decisions

reliability

scatterplots

signal-to-noise ratio

significance level

split-half reliability

squared-error loss agreement

standard error of estimate (SEM)

test information curve

testlets

test-retest reliability

threshold-loss agreement methods

true score

unidimensionality

variance components