The article explores tests to check if a mathematical model fits real-world data well. They focus on equations with small changes over time. The researchers suggest using different tests like Cramér–von Mises and Kolmogorov–Smirnov to see how well the model matches the data. They also look at how these tests perform when the model is slightly different from reality. The study discusses a new way to test the model based on how often it stays close to the real data.