vision
Unaided Distance Vision
Assessment of unaided distance vision of women in Britain.
- Keywords
- datasets
Usage
vision
Details
Paired ordered categorical data from case-records of eye-testing of 7477 women aged 30--39 years employed by Royal Ordnance Factories in Britain during 1943--46, as given by Stuart (1953).
This data set was used by Stuart (1955) to illustrate a test of marginal homogeneity. Winell and Lindb<U+00E4>ck (2018) also used the data, demonstrating a score-independent test for ordered categorical data.
Format
A contingency table with 7477 observations on 2 variables.
Right.Eye
a factor with levels
"Highest Grade"
,"Second Grade"
,"Third Grade"
and"Lowest Grade"
.Left.Eye
a factor with levels
"Highest Grade"
,"Second Grade"
,"Third Grade"
and"Lowest Grade"
.
References
Stuart, A. (1955). A test for homogeneity of the marginal distributions in a two-way classification. Biometrika 42(3/4), 412--416. 10.1093/biomet/42.3-4.412
Winell, H. and Lindb<U+00E4>ck, J. (2018). A general score-independent test for order-restricted inference. Statistics in Medicine 37(21), 3078--3090. 10.1002/sim.7690
Examples
# NOT RUN {
## Asymptotic Stuart test (Q = 11.96)
diag(vision) <- 0 # speed-up
mh_test(vision)
## Asymptotic score-independent test
## Winell and Lindbaeck (2018)
(st <- symmetry_test(vision,
ytrafo = function(data)
trafo(data, factor_trafo = function(y)
zheng_trafo(as.ordered(y)))))
ss <- statistic(st, type = "standardized")
idx <- which(abs(ss) == max(abs(ss)), arr.ind = TRUE)
ss[idx[1], idx[2], drop = FALSE]
# }