Data on the average number of births and deaths by the time of the day for a particular hospital in Brussels. The data cover a 30-year period in the nineteenth century.
Usage
data(Berk)
Arguments
source
Berk, R. A. (1990). A primer on robust regression. In Fox, J. and Scott Long, J. (Eds), 292-324. Modern Methods of Data Analysis. Sage Publications, Newbury Park, Ca, USA.
Details
Twenty-two observations are clustered and show little association. Two observations (for noon and midnight) are dramatically smaller in both the y-direction and x-direction. With these two included, there is obviously a positive correlation in the data. However, a direct association between the two variables is doubtful, for if the outliers are removed then all correlations decrease and the associated p-values increase up to the point where the null hypothesis of independence cannot be rejected at any reasonable level.