vision {coin} | R Documentation

## Unaided Distance Vision

### Description

Assessment of unaided distance vision of women in Britain.

### Usage

    vision

### 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"`.

### 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).

Stuart (1955) used this data set to illustrate a test of marginal homogeneity.

### Source

Stuart, A. (1953). The estimation and comparison of strengths of association in contingency tables. Biometrika 40(1/2), 105–110.

### References

Stuart, A. (1955). A test for homogeneity of the marginal distribution in a two-way classification. Biometrika 42(3/4), 412–416.

### Examples

    ## Asymptotic Stuart(-Maxwell) test (Q = 11.96)
    diag(vision) <- 0 # speed-up
    mh_test(vision)

[Package coin version 1.1-3 Index]