rootogram for normal distributions
The normal distribution is a continuous distribution, i.e., the frequency for each observed value will essentially be 1/n and not converge to the density function. Hence, you would need to look at histogram or smoothed densities. Rootograms, on the other hand, are intended for discrete distributions.
I don't think that's true - rootograms are useful for both continuous and discrete distributions. See (e.g.) p 314 at http://www.edwardtufte.com/tufte/tukey, where Tukey himself uses a rootogram with a normal distribution. Hadley
Assistant Professor / Dobelman Family Junior Chair Department of Statistics / Rice University http://had.co.nz/