The estimation of reliability when several trials are available

In certain types of experiment it frequently happens that we have a block of data consisting of several trials on the same individuals. Using the methods of estimation provided by the analysis of variance, estimates of reliability are derived for this case, and the conditions under which each is valid are discussed. Various relations between these estimates and the product-moment coefficient of correlation are obtained.From the Laboratory of Physiological Hygiene, University of Minnesota. This work was supported in part under the terms of a contract between the Regents of the University of Minnesota and the Office of Scientific Research and Development. Important financial assistance was also provided by the Nutrition Foundation, Inc.: The U. S. Sugar Cane Refiners Association, N. Y.; the Corn Industries Research Foundation, N. Y.: Swift and Co., Chicago; the National Confectioners' Association; the National Daily Council, Chicago; and the Graduate Medical Research Fund. University of Minnesota. The author is indebted for assistance and encouragement to all the members of the staff of the Laboratory of Physiological Hygiene, and especially to Mr. Harold Guetzkow and Mr. Rich and Seymour.