The Unit of Analysis and the Independence of Observations (UMAP)

This module addresses two problems that have received insufficient attention in the statistical literature, namely, the selection of an appropriate unit of analysis and the determination of the independence of a set of observations that comprise aggregated data. An example from research on twins is used throughout the module. Exercises, an annotated bibliography, and an end-of-module quiz are included.

Table of Contents:

INTRODUCTION

AN EXAMPLE INVOLVING REAL DATA

THE UNIT OF ANALYSIS

THE INDEPENDENCE OF OBSERVATIONS

SOME ADDITIONAL COMMENTS REGARDING I

TOTAL, BETWEEN, AND WITHIN CORRELATION COEFFICIENTS

BUT WHICH CORRELATION IS THE RIGHT CORRELATION FOR THE TWIN DATA?

HOW ABOUT CONTROLLED EXPERIMENTS?

SUMMARY

ANNOTATED BIBLIOGRAPHY

END-OF-MODULE QUIZ

ANSWERS TO EXERCISES

ANSWERS TO QUIZ

APPENDIX