Unaided Distance Vision
Assessment of unaided distance vision of women in Britain.
vision
A contingency table with 7477 observations on 2 variables.
Right.Eyea factor with levels "Highest Grade", "Second Grade",
"Third Grade" and "Lowest Grade".
Left.Eyea factor with levels "Highest Grade", "Second Grade",
"Third Grade" and "Lowest Grade".
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 Lindbäck (2018) also used the data, demonstrating a score-independent test for ordered categorical data.
Stuart, A. (1953). The estimation and comparison of strengths of association in contingency tables. Biometrika 40(1/2), 105–110. doi: 10.2307/2333101
Stuart, A. (1955). A test for homogeneity of the marginal distributions in a two-way classification. Biometrika 42(3/4), 412–416. doi: 10.1093/biomet/42.3-4.412
Winell, H. and Lindbäck, J. (2018). A general score-independent test for order-restricted inference. Statistics in Medicine 37(21), 3078–3090. doi: 10.1002/sim.7690
## 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]Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.