Quality and Reliability Methods - SAS

Chapter 10 Variability Charts 175
Attribute Gauge Charts
x ij
( N i
– x ij
)
x ij
ˆ
κ j
1 ---------------------------------------------------
i = 1
i = 1
= – where p
n
j = ----------------
n
q j = 1 – p j
( p j q j ) N i
( N i
– 1)
N i
i = 1
i = 1
and the overall kappa is
κˆ
p j q j
j = 1
The variance of κ j and κ are
n
k
ˆ
q j p j κ j
=
j------------------------
= 1
k
var( κˆ j)
2
= -------------------------
nN( N – 1)
k
var κˆ
2 k
2
( ) = ------------------------------------------------------
k 2 × p j q
j –
p j q j ( q j – p j )
p j q
j = 1 j = 1
j nN( N – 1)
j = 1
The standard errors of κ j and κ are shown only when there are an equal number of ratings per subject (for
example, N i = N for all i =1,…,n).
n