Nomographs for the Significance of the Difference Between Percentages
M. Reeb · Educational and Psychological Measurement · 1972
cance of the difference between uncorrelated percentages, based on the &dquo;development of a statistic which is a function of p and which has a constant standard error dependent only on the size of the sample.&dquo; This nomograph, Figure 1 in the present paper,2 is con-venient to use in that it provides, directly from pi and p2, values for the statistic ~ (omega) for substitution in the calculation being completed arithmetically 3 The first part of this paper suggests the use of a companion nomograph providing directly that part of (1) which is a function of Ni and N2. This function, defined as v (nu), gives rise to which is more easily calculated than (1). The nomograph is based on the geometric property that in a right-angled triangle of lesser sides Nl and N2, if a line be drawn 1 The publication of this material has been assisted by a grant from the