An important area of biochemical medical research is in the development of antitumor drugs, where interest lies in being able to predict a drug's activity using properties of its chemical structure. Since the resultant biological measures possess large variability they are often analyzed using order statistics. The following data are given by Mager (1980a) where
Y1 = Harmmett's electronic constant
Y2= Electronic constant in a different position
Y3 = Logarithm of molar volume
(a) Using the original observations carry out a principal components analysis of the variables.
(b) Perform a principal components analysis using quartiles in place of the original observations, What do you conclude?