JOHN MANDEL National Bureau of Standards Washington 25, D. C. A serious limitation in the use of latin squares is the confounding of the main effect of each factor with the interaction of the remaining two factors. In some cases, the interaction of rows and columns can be expressed as a Read more
J. EDWARD JACKSON Virginia Polytechnic Institute* The methods described in an earlier article devoted to control methods for two related variables are extended to the case of more than two related variables. The concept of matrix notation is introduced because of the resultant simplification in Read more
ALLANBIRNBAUM New York University This paperd iscussesse veraml ethodsfo r judgingw hich of m contra& provided by a factoriald esignw ithout replication may be different from zero. These include the techniqueo f half-normal plotting, proposed by C. Daniel, forwhich someo perating Read more
CUTHBERT DANIEL New York City Plotting the empirical cumulative distribution of the usual set of orthogonal contrasts computed from a 2p experiment on a special grid may aid in its criticism and interpretation. Bad values, heteroscedasticity, dependence of variance on mean, and some types of Read more
W. J. YOUDEN National Bureau of Standards Interlaboratory and round robin test programs can provide information, not only on a test procedure under investigation, but on the participating laboratories as well. A simple graphical technique is proposed to aid in the comparisons between Read more