Assignment to Treatment Group on the Basis of a Covariate

  title={Assignment to Treatment Group on the Basis of a Covariate},
  author={Donald B. Rubin},
  journal={Journal of Educational Statistics},
  pages={1 - 26}
  • D. Rubin
  • Published 1 March 1977
  • Mathematics
  • Journal of Educational Statistics
When assignment to treatment group is made solely on the basis of the value of a covariate, X, effort should be concentrated on estimating the conditional expectations of the dependent variable Y given X in the treatment and control groups. One then averages the difference between these conditional expectations over the distribution of X in the relevant population. There is no need for concern about “other” sources of bias, e.g., unreliability of X, unmeasured background variables. If the… Expand

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