R: Comparison of Water Filters

waterfilter {ANOM} | R Documentation

## Comparison of Water Filters

### Description

Filtering performances of seven brands of water filters, measured as the number of bacterial colonies growing on each device.

### Usage

    data(waterfilter)

### Format

A data frame with 20 observations on the following 2 variables.

`brand`

  A factor with 7 levels giving the brands of water filters.

`colonies`

  A numeric vector giving the number of bacterial colonies found on each filter.

### Details

A high number of bacterial colonies on a filter corresponds to good performance of this particular device. Note that the dataset is unbalanced (n=2 for brands 4 and 7, n=3 for all other brands).

### Source

Hsu, J. C. (1984) Ranking and selection and multiple comparisons with the best. In: Santner, T. J. and Tamhane, A. C. (Editors) Design of Experiments: Ranking and Selection (Essays in Honor of Robert E. Bechhofer). Marcel Dekker, New York, NY, pp. 23–33.

### References

Westfall, P. H., Tobias, R. D., Wolfinger, R. D. (2011) Multiple Comparisons and Multiple Tests Using SAS, Second Edition. SAS Institute Inc., Cary, NC, pp. 592–593.

### Examples

    data(waterfilter)
    str(waterfilter)

[Package ANOM version 0.5 Index]