R.A. Fisher and Karl Person

Founders of modern applied statistics


R.A. Fisher (1890-1962)

  • Revolutionized statistics with the concept of “likelihood,” and maximum likelihood parameter estimation rather than “method of moments.”
  • Stated that the “Information” contained in a random sample is inversely related to its variance.
  • Wrote the first book on Design-of-Experiments.
  • Corrected the inventor of the Chi-square test statistic, introducing the concept of degrees-of-freedom.
  • Formalized “Student’s” ideas on the influence of small sample sizes.


Karl Pearson (1857-1936)

  • Developed the “Method of Moments,” for estimating statistical model parameters by equating the empirical monents  with the corresponding theoretical ones.
  • Chi distance. A precursor and special case of the Mahalanobis distance
  • p-value. (Unfortunately, very often misused)
  • Suggested the foundations of the statistical hypothesis testing and statistical decision theory
  • Invented Pearson’s chi-squared test.
  • Suggested rudimentary principal component analysis.