Learn how to systematically determine and validate modeling and theoretical uncertainties in scientific research through this 31-minute lecture by Stefano Forte from IPhT-TV. Explore methodological approaches for quantifying uncertainties that arise from theoretical assumptions and modeling choices in scientific calculations. Discover techniques for assessing the reliability of theoretical predictions and understanding the limitations inherent in mathematical models. Examine validation strategies that help researchers evaluate whether their uncertainty estimates accurately reflect the true precision of their theoretical results. Gain insights into best practices for communicating theoretical uncertainties and their implications for experimental comparisons and scientific conclusions.