Listen now | Early in our education about science, we learn that to understand what is happening in a system, we can only change one variable at a time. That seems reasonable. By doing that, we can see which variables matter. It turns out that this is not only slow, but in biology, but possibly incomplete. If there is a two-factor interaction (not uncommon) you will miss it. The good news is that it’s possible to analyze many variables at the same time and understand which ones matter. One can also see the interdependence of multiple factors.