Many medical researchers believe that it would be fruitless to submit for publication any paper that lacks statistical tests of significance. Their belief is not ill founded: editors and referees commonly rely on tests of significance as indicators of a sophisticated and meaningful statistical analysis, as well as the primary means to assess sampling variability in a study. The preoccupation with significance tests is embodied in the focus on whether the P value is less than 0.05; results are considered "significant" or "not significant" according to whether or not the P value is less than or greater than 0.05. Dr. . . .