Multi modality is an exchange between a device and a human where multiple input or output modalities can be used simultaneously or sequentially, depending on context and preference.
There are greater burdens on your customer research to understand your customer's context use and to understand what form of multimotal manifestation make sense for your customers.
Cheryl Platz is an accomplished interaction designer who has designed multimodal experiences for Amazon, Microsoft, the Walt Disney Company and more. The focus of our conversation is her new book on the subject, Design Beyond Devices.