Choosing the right level of abstraction in simulations is a critical yet often overlooked challenge. STRATA (Scoring Tool for Rational Abstraction Tradeoff Analysis) offers a structured, domain-independent framework to evaluate and select optimal abstraction levels based on nine clear criteria: fromexplanatory power to computational efficiency. This article introduces STRATA, explains its methodology and walks you through a real-world example in biology to help you apply it in your own.