Shaheed Azaad, Patric Bach, Anna Zamm, Natalie Sebanz (2026) ·
Publications
Preprints and articles.
Total 23 Page 1 of 6
Henrike Maria Jungeblut, Shaheed Azaad (2026) ·
Liu et al. (2024) recently published a systematic review and meta-analysis of studies on vaccine promotion interventions. One key finding highlighted in the study’s abstract is that strategies that increased access to vaccines were especially effective in lower-income countries and those with limited healthcare access. Here, we raise two issues that call this finding into question. First, Liu et al.’s dataset contains no studies in which access interventions are implemented in low- or even middle-income countries, meaning that any claims about the efficacy of access interventions in these regions are extrapolated from a pattern so far observed only in high-income countries. Second, the interaction effect supporting this conclusion appears to be an artifact of the authors’ selecting a model that systematically excluded the largest non-access intervention effects in low- and middle-income...
Robrecht van der Wel, Shaheed Azaad, Pernille Hemmer, John Michael (2026) ·
In a recent meta-analysis, Mariano et al. (2025) conclude that people experience a stronger sense of agency over positive than negative outcomes, indexed by temporal compression. In this commentary, we evaluate that claim and identify several concerns about its robustness. First, we were unable to reproduce their main valence effect: our reconstruction of the three-level meta-analytic model yielded a smaller, non-significant difference. Second, we identified data integrity issues, including implausibly small standard deviations that appear to reflect computational errors. Third, we argue that temporal compression effects should be standardized before being combined, because values in milliseconds are not necessarily comparable across different paradigms. When we analyzed standardized effects, evidence for a valence effect was weak, and absent once adjusting for publication bias. Overall...
Shaheed Azaad (2026) ·
Although power analysis has become increasingly accessible over time, researchers still find it challenging to compute power for complex ANOVA interactions. anovapowersim is an R package that enables users to easily specify between, within, and mixed interactions of varying complexity and simulate power based on a target effect size. This tutorial provides a short introduction to the package's core functionality, along with worked examples and sample R code.