Introduction

On the morning of January 27, 2020, Team Solar Power conducted a usability test on the solar paneled buoy. The team conducted the usability test with the second prototype, which is currently just the base of the buoy with no solar panel at this point. The goal of this round of usability testing is to observe how users might place the data-collecting buoys in and out of the water. It is also to ask users any feedback they have about the buoy. The test results will be used to modify the shape and weight of the buoy. Due to limited access of the pool, we had to do most of our testing in one sitting.

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Background Information about the Users

There were a total of thirteen people who tested the buoy, four members of Team Solar Power, four members of Team Personalized Learning, three biomedical engineering majors, one biology major and one biochemistry major. Among the thirteen, nine were female students and four were male students.

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Quantitative Analysis

For the quantitative measurement of the usability test, one team member was responsible for measuring the time it took for each user to place the buoy in and out of the water. The operational definition for buoy placement was when the buoy was picked up off the ground to when it hit the water. The operational definition for buoy retrieval was when the user touched the buoy to when they let go of the buoy. A chart of this data is shown below.

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Using these measurements, we were able to calculate means and standard deviations of the placement and retrieval times. All mean values are highlighted in green.

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We do not have a large enough sample size to properly test normality, but biological sex does not seem to impact placement or retrieval time of the buoy. Over all, the average placement time is 3.365 seconds while the retrieval time is 3.861 seconds. This seems to be a reasonable amount of time necessary to place and retrieve the solar panel buoy.

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Qualitative Analysis

One team member was responsible for the qualitative analysis of the usability test. In each round of testing, he ranked the following categories based on user feedback and body language. This data is shown for all participants except members of Team Solar Power.

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Users were also asked for feedback on the buoy itself. Almost all users like the rods on top of the buoy to help place and retrieve the buoy. They also said, however, that the rods were extremely uncomfortable because the screws dig into the hands. A solution to that may be adding grips to the rods. 

 

One participant commented that the buoy was not aesthetically pleasing. One solution to that may be to smooth out the expanding foam and clean the edges of the purple foam on the buoy.

 

At one point, we asked a participant to throw in the buoy. When she did this, the buoy landed in the water upside down. While the buoy maintained to float, it did not fix itself to its upright position and instead floated upside down. Other users threw in the buoy and it rocked quite a bit but ultimately stayed upright.

We also tested throwing the buoy from a height. Marine biologists will likely be placing this buoy from a boat. We had one participant stand on the diving board and throw it in from there to simulate this. The buoy rocked a little but it stayed upright.

 

Overall, the weight and ballast of the buoy seemed alright. Participants seemed to be pleased with this aspect of the buoy.

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Conclusion

Overall, the usability test on the solar paneled buoy was successful. The buoy floats, which is very important. The time it takes to place and retrieve the buoy is within reason. Users like the handles, but we need to make them more comfortable. The buoy stays upright unless it is thrown very violently. For the next testing, we would like to test what we’ve tested here, as well as powering the solar panel in the buoy.