Description

Fictitious data set based on results of an experiment where subjects were randomly divided into two groups and given a placebo or vitamin c to take during the cold season. At the end of the cold season, the subjects were interviewed by a physician who determined whether they had or had not suffered a cold during the period. Skeptics interviewed the 800 subjects to determine who knew and who did not know to which group they had been assigned. Vitamin C has a bitter taste and those familiar with it could recognize whether their pills contained it.

Usage

Format

A data frame with 4 observations on the following 4 variables.

Knew

a factor with levels "no" and "yes"

Treatment

a factor with levels "placebo" and "vitC"

Cold

number of people who got a cold

NoCold

number of people who did not get a cold

Source

Ramsey, F.L. and Schafer, D.W. (2002). The Statistical Sleuth: A Course in Methods of Data Analysis (2nd ed), Duxbury.

Examples