Understanding how different species interact in diverse ecosystems can be tricky. Traditionally, scientists focused on species numbers to explain how ecosystems work. But in complex systems, there are too many interactions to study each one. A new method combines fixed values and random effects to better understand how diversity affects ecosystem function. This approach helps to test specific factors and identify any missing information. By using data from grasslands and microbial experiments, researchers found a way to simplify the study of species interactions in diverse ecosystems.