How Do Scientists Use Models? During the current COVID-19 pandemic, you have probably read a lot about scientific models. Scientists rely on models of how systems work to take new data, add that information into a model, and then use the model and new data make predictions. The predictions may be about the future (things we haven’t observed yet), or about the past (things no one was around to record). You have likely heard someone downplay such predictions, by saying “it’s only a mo ...