Phones Aren’t Flat: Designing for Real People in Diverse Contexts (Steven Hoober)

People use their phone in real environments and interact with them just as they do with anything else, so we must set aside the assumption that they’re interacting just with a flat, glass screen. The way people hold and tap their phone changes according to their grip—and that changes frequently because they may be carrying items, holding onto children, talking to others, or opening doors. (uxmatters.com)