Designed a reusable set of control modules (Fragrance, Light, Timer, Schedule) that works the same way for Solo, Duo, and Trio devices. This reduced cognitive load, supported quick learning, and reflects the Law of Consistency from by letting users transfer knowledge between device types.
Created clear, tap‑friendly state controls for Off/Low/Medium/High and color‑coded light presets to support mobile ergonomics and Fitts’ Law, drawing on guidance around large touch targets and clear visual hierarchy.
Introduced proactive cartridge messaging (“Almost empty”, “Replace”, and “Multiple cartridges are almost empty”) to prevent confusion and device abandonment. This feedback is grounded in usability research showing that timely status messages reduce support contacts and increase trust in connected products.
Designed the scheduling flow to keep all key decisions (on/off times, intensity per cartridge, days of week) within a single, linear screen. This pattern was influenced by findings that consolidated self‑service flows, reduce task time and abandonment, and by Hick’s Law to limit the number of separate decisions users need to juggle.
Validated the interaction model with mid‑fidelity prototypes, using task‑based usability tests (e.g., “set a weekday evening schedule”, "rename the device" or “turn off one cartridge while leaving the others on”) to refine labeling, default states, and error prevention. Insights from these tests guided microcopy changes and default choices that improved task success and user confidence.
