Wetherill's estimator Co of LD5o for a quantal response curve based on the peaks and troughs of the up-and-down method of an experiment is investigated. In particular, this paper gives general formulas for the expectation and variance of c and of a modified estimator denoted by . The results are applied to the problem of estimating the mean of a normal distribution. Several useful properties of the estimators are discussed and a method of obtaining an unbiased estimator is suggested. Also presented are some numerical comparisons of three estimators in bioassay.
No takes yet. Share an insight, caveat, or question.
Sung C. Choi (1971) studied this question.