Skip to content

Scott's pi coefficient

Jeffrey M Girard edited this page Feb 20, 2016 · 36 revisions

Index Information

Coming soon...

MATLAB Functions

  • FAST_PI %Calculates pi using simplified formulas
  • FULL_PI %Calculates pi using generalized formulas

Simplified Formulas

pi

pi

pi

pi

pi

Use these formulas with two raters and two categories (dichotomous).

a is the number of items both raters assigned to the first category

d is the number of items both raters assigned to the second category

n is the total number of items

f_1 is the number of items rater A assigned to category 1

f_2 is the number of items rater A assigned to category 2

g_1 is the number of items rater B assigned to category 1

g_2 is the number of items rater B assigned to category 2

Contingency Table

Generalized Formulas

References

  1. Scott, W. A. (1955). Reliability of content analysis: The case of nominal scaling. Public Opinion Quarterly, 19(3), 321–325.
  2. Fleiss, J. L. (1971). Measuring nominal scale agreement among many raters. Psychological Bulletin, 76(5), 378–382.
  3. Siegel, S., & Castellan, N. J. (1988). Nonparametric statistics for the behavioural sciences. New York, NY: McGraw-Hill.
  4. Byrt, T., Bishop, J., & Carlin, J. B. (1993). Bias, prevalence and kappa. Journal of Clinical Epidemiology, 46, 423–429.
  5. Gwet, K. L. (2014). Handbook of inter-rater reliability: The definitive guide to measuring the extent of agreement among raters (4th ed.). Gaithersburg, MD: Advanced Analytics.