Ury H K, Fleiss J L
Biometrics. 1980 Jun;36(2):347-51.
An investigator wishes to compare two independent proportions, based on perhaps unequal sample sizes, by means of the chi squared test with the Yates' correction. A simple approximation is given to the sample size(s) required for the Yates-corrected chi squared test to have specified power; it is then compared with other approximations and with the exact sample size for the equal sample case. In that case the proposed approximation is quite similar to the approximate formula recently put forward by Casagrande, Pike and Smith (1978, Biometrics 34, 483-486).
一名研究者希望通过采用带有耶茨校正的卡方检验，基于可能不相等的样本量来比较两个独立比例。针对经耶茨校正的卡方检验要达到特定功效所需的样本量，给出了一个简单的近似值；然后将其与其他近似值以及等样本量情况下的精确样本量进行比较。在那种情况下，所提出的近似值与卡萨格兰德、派克和史密斯最近提出的近似公式（1978年，《生物统计学》34卷，483 - 486页）颇为相似。
