Design justification CER

Claim: Our lobby wayfinding kiosk design meets the navigation needs of our two target users at a large hospital, an older first-time visitor named Ellen and a hurried delivery driver named Marcus.\n\nEvidence (persona and feature list): Ellen needs to reach a department she has never visited and reads slowly, so we made the home screen a single large question, "Where are you going?", with a short list of the most-visited departments in big high-contrast text. Marcus needs the loading dock and its entrance quickly and only glances at the screen, so we added a persistent "Deliveries and Dock" button in the same fixed spot on every screen and a printable step-by-step route card.\n\nReasoning (tie each choice to a usability principle): The single-question home screen serves simplicity, because it removes competing choices and shows one clear task at a time. The big high-contrast text serves accessibility, so a user with weaker vision like Ellen can still read it without help. The fixed-position "Deliveries and Dock" button serves consistency, because Marcus can find the same control in the same place every time and does not have to relearn the screen. The printable route card serves memory support, so a user does not have to hold every turn in their head while walking a long hallway.\n\nPrediction: Because the design cuts the reading load and the number of choices that usually make people freeze or ask staff for help, more visitors should reach the right department on their own and fewer should crowd the information desk, which is the behavior change we want in a busy lobby.\n\nAssumptions and limitations: We assume our two personas represent most kiosk users, that visitors can stand and touch a screen, and that department names on the kiosk match the signs in the hallways. If many users are in wheelchairs and cannot reach a tall screen, or if the building signs use different names than the kiosk, then the design would fail those users and our claim would need to change. A lower screen height and matching signage would matter more than any button we added.