“Use Modal Screens for self-contained processes, use Non-Modal Screens for everything else.
Use Modal Screens for critical information that requires a specific user task, decision, or acknowledgement.
Try to minimize the use of modality. Generally, people prefer to interact with apps in nonlinear ways. Consider creating a modal context only when it’s critical to get someone’s attention, when a task must be completed or abandoned to continue using the app, or to save important data. “
Intrigued? Read the full article by Fabian Sebastian at the following link: