usability

Usability is a human-made quality attribute of interactive systems that measures how effectively, efficiently, and satisfactorily specified users can achieve specified goals in a given context of use. It carves by requiring (1) identifiable users with defined capabilities and intentions, (2) specific goals the system is designed to support, (3) measurable performance dimensions — learnability (how quickly a new user can perform basic tasks), effectiveness (accuracy and completeness with which users achieve goals), efficiency (resources expended relative to accuracy), satisfaction (comfort and acceptability), and memorability (how easily proficiency is retained after a period of non-use). It persists through evaluation frameworks (heuristic evaluation, usability testing, A/B testing), design standards (ISO 9241), and the practice of iterative user-centered design. [formal: usabilitas | substrate: behavior | horizon: hours | explicit: yes | epoch: 0.01]