Things made to be used: form, function, users and the systems that produce them.
Ways in
Usability testing, practice research, historical analysis, critical theory.
The longer story
Design objects surround us—furniture, appliances, tools, everyday things shaped by someone's decisions. Design research studies both process (how designers work) and product (how objects function and mean). Usability testing measures whether things work. Historical analysis traces design evolution. Critical design asks what design could do differently. The challenge is that design often succeeds by disappearing—the best doorknob doesn't make you think about doorknobs.