Integrating Informative Hypotheses Into the EffectLiteR Framework

Authors

  • Caroline Keck
    Department of Data Analysis, Ghent University, Ghent, Belgium
  • Axel Mayer
    Psychological Methods and Evaluation, Bielefeld University, Bielefeld, Germany
  • Yves Rosseel
    Department of Data Analysis, Ghent University, Ghent, Belgium

Abstract

Using the EffectLiteR framework, researchers can test classical null hypotheses about effects of interest via Wald and F-tests, while taking into account the stochastic nature of group sizes. This paper aims at extending EffectLiteR to test informative hypotheses, assuming for example that the average effect of a new treatment is greater than the average effect of an old treatment, which in turn is greater than zero. We present a simulated data example to show two methodological novelties. First, we illustrate how to use the Fbar- and generalized linear Wald test to assess informative hypotheses. While the classical test did not reach significance, the informative test correctly rejected the null hypothesis, indicating the need to take into account the order of the treatment groups. Second, we demonstrate how to account for stochastic group sizes in informative hypotheses using the generalized non-linear Wald statistic. The paper concludes with a short data example.