Preregistration can help to restrict researcher degrees of freedom and thereby ensure the integrity of research findings. However, its ability to restrict such flexibility depends on whether researchers specify their study plan in sufficient detail and adhere to this plan. Previous research indicates higher restrictiveness when preregistrations are based on structured versus unstructured template formats, although there is room for further improvement. In this study, we built on these findings and investigated the restrictiveness of preregistrations based on the Psychological Research Preregistration-Quantitative (PRP-QUANT) Template, an extensive template that aids the preregistration of quantitative studies in psychology. Preregistrations were sampled from PsychArchives and coded for their level of restrictiveness using the coding schemes of Bakker et al. and Heirene et al. We predicted that preregistrations based on the PRP-QUANT Template ( N = 103) are more restrictive than preregistrations based on the OSF Preregistration Template ( N = 52; Hypothesis 1). We also inspected whether peer review can contribute further to restricting flexibility using nested Wilcoxon-Mann-Whitney tests and predicted higher restrictiveness for peer-reviewed ( n = 29) than non-peer-reviewed preregistrations ( n = 74; Hypothesis 2). In addition, we examined adherence to the preregistered plans in the associated publications ( N = 19). In line with Hypothesis 1, PRP-QUANT preregistrations had significantly higher restrictiveness scores than OSF preregistrations. Moreover, consistent with Hypothesis 2, peer-reviewed preregistrations had significantly higher restrictiveness than non-peer-reviewed ones. Of the associated articles, 73.68% included undeclared deviations. We discuss the implications of our findings for the PRP-QUANT Template and structured templates in general.
Spitzer et al. (2026) studied this question.