Behavioral Prototype: Gesture-Controlled Lamp

Prototype

For this assignment, we were to design a prototype for one scenario, out of a few options given to us:

• Applications for a voice-operated assistant
• Gesture recognition platform
• Chatbot or text messaging app

To design this prototype, we used the Wizard of Oz technique, which involves the simulation of a digital or physical product for a user to interact with. The technique is helpful for understanding how a user would interact with the device if it were real and fully functional.

Our group decided to create a gesture recognition system for a lamp, which would allow the user to turn the lamp on and off, to adjust their brightness, and to make the light warmer or cooler.

• Push/tap gesture signals the lamp to turn on/off
• Up and down gesture signals the lamp to raise or lower the brightness
• Left and right gesture signals the lamp to be cooler or warmer color
• Lamp color turns red for a second when a gesture is detected but not recognized (error case)
• Lamp motion detector is meant to be invisible to user so that it is aesthetically pleasing
• User must be maximum 3 feet away from lamp for motion detector to sense the gestures

The lamp at different settings: off, cool, and warm

Our evaluation focused on two key criteria — usability and impact. Usability was measured by observing how easily participants learned and performed the gestures after the demonstration video, how confident they felt using them, and how intuitive they recalled them during task scenarios. We collected qualitative data through facial expressions, general reactions, and open-ended questions about which gestures felt intuitive or confusing, and whether they experienced any obstacles. We assessed impact by gauging how desirable or practical participants found the gesture-controlled lamp in everyday life. We asked open-ended questions about whether they would want to use such a system, in what contexts it would be helpful, and what additional features they’d like to see. Then, we asked them to show us how they would communicate to the system to control their desired command. These methods allowed us to evaluate not only how effectively users could operate the prototype, but also how meaningful and valuable they viewed the experience.

When planning how to design the prototype and how we would perform the user test, we first assigned roles for the team:

• Facilitator (Hannah): Directs the user testing
• Wizard (Ally): People behind the curtain who make sure the tasks and features align with the user’s hand gestures
• Scribe (Simone): Takes notes during user test about how the user interacts/learns the gestures, user pain-points, how the prototype performed
• Documentarian (Ziyi): Captures the user test on video

The goal was to simulate a real-time interaction between a user and a gesture-recognition lamp without actually building complex motion-sensing hardware. Instead, it is a built-on of an existing product where a team member — the Wizard — secretly controlled the brightness and tone accordingly via an app. This person was physically present in the room with the participant. This setup allowed us to create an illusion of a system that responded to hand motions, allowing us to assess the interaction flow, user expectations, and intuitiveness of the gestures.

Interface of the app that controlled the lamp with different settings: device closed, warm and dim, and bright and cool

After this step, we planned how we would test the user. We decided to create gestures for each of the main functions, to understand how intuitive the gestures are. In addition, we planned for how we would indicate to the user that their gesture was incorrect: a small blink of red light on the lamp. We also created specific tasks for the user:

Task 1: Turn on the lamp and raise the brightness to your liking. Then, change the color of the lamp to be cool, so that you can wake up and focus.

Task 2: Lower the brightness and make the color more warm

Task 3: Turn off the light like how you would when you’re ready for bed

[embed]Behavioral Prototype User Testing

Analysis

After conducting a usability test for our prototype, we were able to receive feedback from the user. There were many aspects of our prototype that were successful. First, we noticed that the user was able to pick up and remember the hand gestures very well. In addition, we learned that the device (if it were an existing device) would be helpful for the user for studying, going to bed, and/or hosting.

We also learned that there were some additional features that the user would want to see, along with what hand gestures the user would imagine with them. These features include an alarm/timer (set by clapping), music (set when the user places headphones on their head), and different colors (hand gesture along the shape of a rainbow). They also mentioned that it would be nice to have the device be programmable for their daily schedule.

While the test went smoothly, there were also a couple of aspects of the prototype that were confusing for the user. The user was confused about which direction (left or right) would correspond to the warm and cool settings. Another thing they were confused about at first was related to what hand gestures would count as “errors” for the prototype. They also mentioned that we should consider how the light may work in larger spaces. We did the testing in a smaller room, and they felt that the lamp worked great for the space, but that it may be harder to sense motion in larger spaces.

Then, we had an in-class critique where other peers had the chance to review our user-test video. A review from one of our peers stated that they thought that perhaps the user was prompted or already knew the gestures prior to the test, and it appeared that the video could be “faked.” Because of this, we then made sure to add in the clip of the participant learning the gestures to control the lamp in a revised version of the video. Another review also commented that the user-test perhaps could have been improved if the lamp’s actions were not as delayed.

If we were able to take the prototype further, one of the ways we would improve it would be to make sure that the wizard was a bit more on time in connection with the user’s gestures to improve believability. In terms of user testing, something that we would also like to try out in the future is to have the user do any task/gestures that they desire and the wizard would then do the actions through the app. This also would just help with making the user believe the prototype is real and less “set up”.

Reflection

Overall, our team enjoyed working on the behavioral prototype. It was a really great learning exercise about how to prototype in teams together, especially since we had only worked on individual projects in the class before. We also really enjoyed the sort of “faking out” aspect that happens with Wizard of Oz prototyping, and it was satisfying to see the participant realize that the prototype was not “real.” This method allowed us to test assumptions, gather user feedback, and observe interaction flows in a low-cost environment. As we focused on human behavior rather than technical limitations, we realized the value of this prototyping method to explore and validate user interaction before committing to expensive or time-consuming technical development.