Guest Stephen Senn, an expert in causal inference and clinical trials, delves into the myths of randomization and the limitations of randomized trials in answering causal questions. He discusses the importance of understanding mechanisms of change, considering covariates, and the ethical challenges in clinical trials. Senn also explores innovative trial designs in asthma and chronic diseases, the impact of covariates in statistical analyses, and critiques the Bayesian method while engaging in philosophical discussions on determinism and free will.