Causal inference in education research is crucial for assessing the effectiveness of educational policies, programs, and interventions. Establishing causal relations, that is, identifying interventions that actually work in practice, helps policymakers, educators, and researchers implement strategies that are genuinely beneficial, ensuring resources are allocated efficiently to enhance educational experiences and outcomes. Without rigorous causal inference based on experimental or quasi-experimental designs, efforts to improve education might rely on practices that appear effective but fail to produce actual benefits when scaled or applied in different contexts.The main challenge with causal inference is that data alone are insufficient to reliably assess whether a causal relation between two variables of interest-the treatment conditions and the outcome-exists. In other words, data are uninformative about the causal relation of observed variables (Cunningham, 2021;Pearl & Mackenzie, 2018). Causal inference needs more than data. It also needs reliable * Peter M. Steiner