01 / Human limits
People cannot carry the whole system in their heads.
Attention, working memory, perception, confidence, expertise, sensory and motor ability, time, and energy all vary by moment and person.
attentionmemoryperceptionconfidenceabilitytime and energy
Sequence demands, preserve context, use plain language, support assistive technology, protect important decisions, and make recovery obvious.
02 / System limits
Technology does not know, predict, or recover perfectly.
Data is incomplete. Models are uncertain. Permissions, latency, ownership, maintenance, organizational capacity, and accountability shape what a system can safely do.
missing datauncertaintypermissionslatencyownershipaccountability
Show provenance and uncertainty, define boundaries, design failure paths, preserve human handoff, and never hide responsibility behind automation.
03 / Living limits
Every digital product is also a physical arrangement.
Software depends on energy, minerals, devices, logistics, human labor, maintenance, ecosystems, and consequences that may appear far from the interface.
energymaterialslabormaintenanceecosystemsfuture consequences
Treat extraction, consumption, longevity, repair, and ecological cost as design constraints rather than invisible externalities.