Machinists Accidents

A small count data set involving 414 machinists from a three months study, of accidents around the end of WWI.

data(machinists)

Format

A data frame with the following variables.

accidents

The number of accidents

ofreq

Observed frequency, i.e., the number of machinists with that many accidents

Details

The data was collected over a period of three months. There were 414 machinists in total. Also, there were data collected over six months, but it is not given here.

Source

Incidence of Industrial Accidents. Report No. 4 (Industrial Fatigue Research Board), Stationery Office, London, 1919.

References

Greenwood, M. and Yule, G. U. (1920). An Inquiry into the Nature of Frequency Distributions Representative of Multiple Happenings with Particular Reference to the Occurrence of Multiple Attacks of Disease or of Repeated Accidents. Journal of the Royal Statistical Society, 83, 255–279.

See also

negbinomial, poissonff.

Examples

machinists
#>   accidents ofreq
#> 1         0   296
#> 2         1    74
#> 3         2    26
#> 4         3     8
#> 5         4     4
#> 6         5     4
#> 7         6     1
#> 8         8     1
mean(with(machinists, rep(accidents, times = ofreq)))
#> [1] 0.4830918
 var(with(machinists, rep(accidents, times = ofreq)))
#> [1] 1.010609
if (FALSE)  barplot(with(machinists, ofreq),
          names.arg = as.character(with(machinists, accidents)),
          main = "Machinists accidents",
          col = "lightblue", las = 1,
          ylab = "Frequency", xlab = "accidents")  # \dontrun{}