When to adapt
Material Design is built on a foundation of best practices in the fields of both traditional and web design, and is informed by user experience research and cognitive science. The design guidelines that developed from research findings are intended to be applied universally across all platforms and devices.
Design conventions differ from platform to platform. These differences in convention can affect the user's ability to understand the UI or complete certain tasks. In such cases, it’s recommended to adapt to platform-specific conventions. In areas where design differences are minimally disruptive, adapting to the platform is optional.
The following guidelines indicate when to adapt to native platform conventions and adaptation is optional. Platform conventions constantly evolve, and Material Design is evolving with them to increase the quality of our design patterns.