Directional Assist: A Behavioral Prototyping Practice

In this prototyping practice, my group and I chose to build up a Vision-impaired navigation aid system. The biggest challenge was, to build and test this product using “the Wizard of Oz” trick, without making the participant realizing that it’s “fake” during the test.

In order to make this happen, we designed the whole test really carefully.

Test Equipment

We had the choices of either using voice command generated from online text reader or vibrators. We picked vibrators because there will very likely be a delay of feedback when the “wizard” types out the instruction on the tool for it to read.

Test Environment

We picked the CoMotion MakerSpace as our test environment, because it’s neither too loud nor too quiet. Also, the presence of other students can help us hide our “wizard”. So when they are controlling the device on the test user, they can just pretend to be students hanging out in the MakerSpace.

Test User

Unlike some groups using classmates as test users, we invited our friends who have no idea about this assignment as our test users. That is because using classmates as test user might bias the test result, since they already have a rough idea about what the possible project topics.

And this is what happened during the actual test:


Generally speaking the tests were successful. Both test users made it through the maze without having too many collisions with the chairs. And neither of them found out that the test was “faked” until we revealed the truth at the very last moment.

However, they both claimed that they couldn’t really tell which phone(vibrator) is vibrating, because when three phones are inserted into the belt side by side anyone of them will make the adjacent one vibrate. In order to improve that, we believe that using smaller vibrators will make that better. Also, it would be much better if the vibration strength is adjustable, so that it can also reflect the obstacle’s distance to the user.

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