There isn't one specific term for when scientists follow the scientific method. It's more a general principle that underpins their work. However, here are some phrases you could use:

* Conducting scientific research: This emphasizes the overall process of investigation.

* Employing the scientific method: This is a more direct way of stating they are using the method.

* Following a rigorous approach: This highlights the strictness and objectivity of the scientific process.

* Using empirical evidence: This points to the reliance on observable data and experiments.

* Engaging in systematic inquiry: This emphasizes the structured and organized nature of the scientific method.

Ultimately, the best way to describe it depends on the specific context and what you want to emphasize.