2 Responses

1. here’s the YouTube video of the same song:
   

2. Dear Professor Blattman

   Occasionally your blog postings are just FABULOUS (and more than compensate for us having to read about Canada). I feel the need to respond with an old but still very relevant piece (not rap but close) that a good friend sent me when he heard the rapping on your blog. Here goes:

   Hiawatha Designs an Experiment

   Hiawatha, mighty hunter,
   He could shoot ten arrows upward,
   Shoot them with such strength and swiftness
   That the last had left the bow-string
   Ere the first to earth descended.
   This was commonly regarded
   As a feat of skill and cunning.
   Several sarcastic spirits
   Pointed out to him, however,
   That it might be much more useful
   If he sometimes hit the target.
   “Why not shoot a little straighter
   And employ a smaller sample?”
   Hiawatha, who at college
   Majored in applied statistics,
   Consequently felt entitled
   To instruct his fellow man
   In any subject whatsoever,
   Waxed exceedingly indignant,
   Talked about the law of errors,
   Talked about truncated normals,
   Talked of loss of information,
   Talked about his lack of bias,
   Pointed out that (in the long run)
   Independent observations,
   Even though they missed the target,
   Had an average point of impact
   Very near the spot he aimed at,
   With the possible exception
   of a set of measure zero.
   “This,” they said, “was rather doubtful;
   Anyway it didn’t matter.
   What resulted in the long run:
   Either he must hit the target
   Much more often than at present,
   Or himself would have to pay for
   All the arrows he had wasted.”
   Hiawatha, in a temper,
   Quoted parts of R. A. Fisher,
   Quoted Yates and quoted Finney,
   Quoted reams of Oscar Kempthorne,
   Quoted Anderson and Bancroft
   (practically in extenso)
   Trying to impress upon them
   That what actually mattered
   Was to estimate the error.
   Several of them admitted:
   “Such a thing might have its uses;
   Still,” they said, “he would do better
   If he shot a little straighter.”
   Hiawatha, to convince them,
   Organized a shooting contest.
   Laid out in the proper manner
   Of designs experimental
   Recommended in the textbooks,
   Mainly used for tasting tea
   (but sometimes used in other cases)
   Used factorial arrangements
   And the theory of Galois,
   Got a nicely balanced layout
   And successfully confounded
   Second order interactions.
   All the other tribal marksmen,
   Ignorant benighted creatures
   Of experimental setups,
   Used their time of preparation
   Putting in a lot of practice
   Merely shooting at the target.
   Thus it happened in the contest
   That their scores were most impressive
   With one solitary exception.
   This, I hate to have to say it,
   Was the score of Hiawatha,
   Who as usual shot his arrows,
   Shot them with great strength and swiftness,
   Managing to be unbiased,
   Not however with a salvo
   Managing to hit the target.
   “There!” they said to Hiawatha,
   “That is what we all expected.”
   Hiawatha, nothing daunted,
   Called for pen and called for paper.
   But analysis of variance
   Finally produced the figures
   Showing beyond all peradventure,
   Everybody else was biased.
   And the variance components
   Did not differ from each other’s,
   Or from Hiawatha’s.
   (This last point it might be mentioned,
   Would have been much more convincing
   If he hadn’t been compelled to
   Estimate his own components
   >From experimental plots on
   Which the values all were missing.)
   Still they couldn’t understand it,
   So they couldn’t raise objections.
   (Which is what so often happens
   with analysis of variance.)
   All the same his fellow tribesmen,
   Ignorant benighted heathens,
   Took away his bow and arrows,
   Said that though my Hiawatha
   Was a brilliant statistician,
   He was useless as a bowman.
   As for variance components
   Several of the more outspoken
   Make primeval observations
   Hurtful of the finer feelings
   Even of the statistician.
   In a corner of the forest
   Sits alone my Hiawatha
   Permanently cogitating
   On the normal law of errors.
   Wondering in idle moments
   If perhaps increased precision
   Might perhaps be sometimes better
   Even at the cost of bias,
   If one could thereby now and then
   Register upon a target.
   Original source:
   Kendall, Maurice (1959). Hiawatha Designs an Experiment. The American
   Statistician 13: 23-24.