− 1.15 ±1.51 vs. 0.32 ±1.02; F[1,39] = 41.6, p < .0001) and nonconverters (−0.86 ±1.41 vs. 0.42 ±0.82; F[1,39] = 29.5, p < .0001), but were in opposite direction and not significant in converters (1.09 ±1.87 vs. 0.25 ±0.70; F[1,39] = 2.02, p = .16). These parametric statistics were corroborated by non-parametric independent-samples Kruskal-Wallis tests for the novel-minus-target difference of this measure, as well as by the Approximate Degrees of Freedom (ADF) test, a robust multivariate F statistic for mixed designs when cell variances are heterogenous (Lix & Keselman, 1995).
