2020 年 40 巻 2 号 p. 69-79
Reproducibility is the essence of a scientific research. Focusing on two-sample problems we discuss in this paper the reproducibility of statistical test results based on p-values. First, demonstrating large variability of p-values it is shown that p-values lack the reproducibility, in particular, if sample sizes are not enough. Second, a sample size formula is developed to assure the reproducibility probability of p-value at given level by assuming normal distributions with known variance. Finally, the sample size formula for the reproducibility in general framework is shown equivalent to the sample size formula that has been developed in the Neyman-Pearson type testing statistical hypothesis by employing the level of significance and size of power.