Modify your design IN WEEK NINE to correct the problems discovered by the cognitive walkthroughs. Then do thinking-aloud studies with two potential users. Ask each user to accomplish one (or more, if you have time) of the tasks defined in the scenarios for task-centered design. For example, you would first describe the "thinking-aloud" process to your subject, and emphasize that you are testing your interface, not their ability. Then, if you were using the scenario described above, you would present your user with a drawing or cardboard mock-up of your design and say: "Imagine yourself getting up at 3 a.m. with a sick child. You decide to sit with the child in the living room. But the living room is cold, so you want to bring the temperature quickly up to 75 degrees. Show me what you would do using this heat control system, and please let me know what you're thinking as you work through the problem." Revise your design to avoid any problems discovered in the thinking-aloud studies. Write up: A brief description of the thinking-aloud studies, with special attention to any problems they discovered. A description of your final interface design. The "design rationale" -- that is, your reasons for the important features of your design. The reasons should generally refer to the scenarios you've used in task-centered design.

This is the design in Week 9.

Designing a user-friendly interface for a smart home thermostat is a complex task that requires careful consideration of the users' needs, the system's capabilities, and the constraints of the design. Here are some recommendations for the design based on the requirements and constraints mentioned:

1. Use a simple and intuitive interface: Since homeowners don't want large, complex controls on their walls, the interface should be designed to be simple, intuitive, and easy to use. The interface should be easy to navigate, with clear and concise labels for all functions. Buttons, dials, and touch screens can be used to provide users with different options for interacting with the interface. The interface should be designed to be visually appealing and easy to read, with clear indicators for each zone and temperature setting.

2. Incorporate a color-coded display: A color-coded display can be used to provide users with a quick and easy way to identify the temperature settings for each zone. Each zone can be represented by a different color, and the display can be updated in real-time to show the current temperature and the temperature settings for each zone.

3. Provide a scheduling feature: To support the cost-saving benefits of presetting the system to keep rooms warm only when they are likely to be in use, the interface should include a scheduling feature that allows users to set different temperatures for each zone at various times during various days of the week. Users should be able to easily modify the settings as needed, with the option to override preset settings for a few hours or a few days when necessary.

4. Include a vacation mode: To support energy savings during vacations, the interface should include a vacation mode that allows users to set a lower temperature for all zones when no one is at home. This can be easily activated and deactivated using a button on the interface.

5. Provide real-time feedback: The interface should provide users with real-time feedback on the temperature settings for each zone, as well as any changes made to the settings. This can be displayed on the interface using an LCD screen or other visual indicator.

6. Consider the physical limitations of the interface: The interface should be designed to fit within the physical constraints of a 4-inch by 6-inch control panel. This may require creative solutions, such as using a touch screen or stylus pad to provide users with additional options for interacting with the interface.

7. Test the interface with users: To ensure that the interface is user-friendly and meets the needs of homeowners, it should be tested with a group of users. Feedback from users can be used to refine the interface and improve its usability and functionality.