Statistics. In the article “Sample size determination in combinatorial chemistry” by Peng-Liang Zhao, Robert Zambias, James A. Bolognese, David Boulton, and Kevin Chapman, that appeared in number 22, October 24, 1995, of Proc. Natl. Acad. Sci. USA (92, 10212–10216), the authors request that the following correction be noted. The sign on the right-hand side of Eq. 10 on line 36, page 10214, is incorrect. The corrected equation is as follows:

10

The authors apologize for this error and thank Dr. Arpad Furka for pointing this out.