32013-03-08 10:17:10localhostconverted to 1.6 markup22007-10-18 15:49:17PeterWatson12007-10-18 15:47:58PeterWatson

McNemar's test is described in the Categorical Data talk here. $$\delta$$ represents the true difference $$p_text{10} - p_text{01}$$ where $$p_text{ij}$$ = P(time 1 = i, time 2 = j) for dichotomous responses measured on each subject at times 1 and 2. H0: $$\delta$$ $$\leq$$ -t or $$\delta$$ $$\geq$$ t HA: -t $$\leq$$ $$\delta$$ $$\leq$$ t Time 2 - + Time 1 - n00 n01 + n10 n11 The R code uses the formulae of Wellek (2003) to test if the observed difference in proportions provides sufficient evidence to say that there is a relationship between times 1 and 2 by comparing the difference in proportions to a specified criterion difference 'tdel' between 0 and 1. $$p_text{01}$$ and $$p_text{10}$$ are estimated using the inputted observed frequencies $$n_text{01}$$ and $$n_text{10}$$ from a sample of size, n. Type II error is beta (usually 0.05). If ind equals 1 then we reject nonequivalence so -t $$\leq$$ $$\delta$$ $$\leq$$ t otherwise we accept the null hypothesis for the given type II error, beta. [TYPE INTO R THE DESIRED INPUTS N, DELTA, N10, N01 AND BETA USING VALUES IN FORM BELOW]. [THEN COPY AND PASTE THE BELOW INTO R] Reference Wellek S (2003) Testing statistical hypotheses of equivalence. Chapman & Hall/CRC Press.