Friday, April 22, 2005

No wonder I'm a B student

Mobius Stripper has a great post today about her student's exams.

  • Pearson’s correlation coefficient relating position of statistics student’s surname in alphabet (46 students wrote the exam) with student’s exam grade: 0.466.
  • Probability that the correlation in a simple random sample of size 46 would be so strong if there were, in general, no correlation between surname and exam grade: less than 1%
  • Regression equation relating student’s grade y to first initial of student’s surname x: y=52+0.94x
  • Predicted grade for Aaron Aaronson: 53%
  • Predicted grade for Ziggy Zuckerman: 76%

So what this shows for the non stats folk is that there is a positive relationship between Last Initial and grades. This however doesn't necessarily prove any kind of causal relations hip, or anything at all since the sample is only 46 students. It would have to be done on a much larger scale to prove anything real. But it is pretty surprising.

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