human-processor-modellisted

# Human Processor Model Use this skill to make a fast, explicit usability estimate from a concrete task. The goal is not false precision; it is to expose where perception, cognition, memory, or motor action makes the flow slow or fragile. ## Inputs Collect or infer: - Target user and relevant constraints: novice/expert, older adult, motor impairment, low vision, stress, interruption risk. - The exact task goal and success state. - The current method: screens, controls, labels, data entry, navigation path, and feedback. - Competing method, if the user wants a comparison. If the UI is not provided, ask for the smallest missing artifact that determines the steps: screenshot, route, prototype, task list, or current implementation path. ## Workflow 1. Define one narrow task, for example "create a refund for order 1042" rather than "use the billing app". 2. Write the observable user steps from start state to success state. 3. Break each step into perceptual, cognitive, motor, and memory operations. 4. State assumptions before calculating: user expertise, reading load, device, input method, error-free path, and whether information can remain visible. 5. Estimate each operation with the defaults below, adjusting only when the interface or user population justifies it. 6. Sum the time and call out bottlenecks separately from the numeric total. 7. Recommend changes that remove whole operations, keep needed information visible, reduce mode switches, or make feedback immediate. #