作業題目：Please run unweighted and Weighted Kappa Statistics using R and SAS.

Kappa Statistics in R

library(psych)
rater1=c(rep(1,21),rep(1,4),rep(0,2),rep(0,22))
#rater1
rater2=c(rep(1,21),rep(0,4),rep(1,2),rep(0,22))
dta=(cbind(rater1,rater2))
#dta
cohen.kappa(cbind(rater1,rater2))
## Call: cohen.kappa1(x = x, w = w, n.obs = n.obs, alpha = alpha, levels = levels)
## 
## Cohen Kappa and Weighted Kappa correlation coefficients and confidence boundaries 
##                  lower estimate upper
## unweighted kappa  0.57     0.76  0.94
## weighted kappa    0.57     0.76  0.94
## 
##  Number of subjects = 49

lower upper 左右信賴區間

data=matrix(c(21, 4,2, 22),ncol=2,byrow=TRUE)
data
##      [,1] [,2]
## [1,]   21    4
## [2,]    2   22
cohen.kappa(data)
## Call: cohen.kappa1(x = x, w = w, n.obs = n.obs, alpha = alpha, levels = levels)
## 
## Cohen Kappa and Weighted Kappa correlation coefficients and confidence boundaries 
##                  lower estimate upper
## unweighted kappa  0.57     0.76  0.94
## weighted kappa    0.57     0.76  0.94
## 
##  Number of subjects = 49

Weighted Kappa Statistics in R

data = matrix(c(11,  3, 1, 1 , 
                 4, 18, 3, 2 , 
                 2,  5,16, 6 ,
                 1,  2, 4,21  ),ncol=4,byrow=TRUE)
data
##      [,1] [,2] [,3] [,4]
## [1,]   11    3    1    1
## [2,]    4   18    3    2
## [3,]    2    5   16    6
## [4,]    1    2    4   21
cohen.kappa(data)
## Call: cohen.kappa1(x = x, w = w, n.obs = n.obs, alpha = alpha, levels = levels)
## 
## Cohen Kappa and Weighted Kappa correlation coefficients and confidence boundaries 
##                  lower estimate upper
## unweighted kappa  0.42     0.54  0.67
## weighted kappa    0.55     0.69  0.82
## 
##  Number of subjects = 100
weights <-matrix(c(1.0  , 0.888, 0.555, 0.0  ,
                   0.888, 1.0  , 0.888, 0.555,
                   0.555, 0.888, 1.0  , 0.888,
                   0.0  , 0.555, 0.888, 1.0  ), ncol=4)
weights
##       [,1]  [,2]  [,3]  [,4]
## [1,] 1.000 0.888 0.555 0.000
## [2,] 0.888 1.000 0.888 0.555
## [3,] 0.555 0.888 1.000 0.888
## [4,] 0.000 0.555 0.888 1.000
cohen.kappa(data, weights)
## Call: cohen.kappa1(x = x, w = w, n.obs = n.obs, alpha = alpha, levels = levels)
## 
## Cohen Kappa and Weighted Kappa correlation coefficients and confidence boundaries 
##                  lower estimate upper
## unweighted kappa  0.42     0.54  0.67
## weighted kappa    0.55     0.69  0.82
## 
##  Number of subjects = 100