🔍 User Testing & Iteration Log

Teams conduct rapid user testing with one visiting user (P.E. teacher if available or a partner team). Students ask the user to interact with the model and explain what they notice about how biking affects the body. Teams document at least 2 user comments or questions, identify one confusion or breakdown, and revise one feature immediately (Version 2). Students update their iteration log to explain what changed and why, using cause-and-effect language connected to heart, lung, and muscle function.