Usability test

The microwave oven


This usability test of the microwave oven is mainly focused on General Electric’s microwave oven — “Profile PEB1590DMWW”. The purpose of this usability test is to examine whether navigation and physical structure design of the “Profile” microwave oven are user-friendly enough or not.

Work summary:

In the beginning, our team members listed possible test appliances for our usability test and we finally chose the “Profile” microwave oven, which is located in Lander Hall (one of the UW’s main residential halls), as our target product, because it is an essential appliance for Lander Hall’s residents. Next, we decided to choose college students as our main target users because they use the microwave oven to cook the microwave oven’s food frequently.

Our target product, “Profile PEB1590DMWW

After that, we began to make our usability plan.

Our team believed “in order to examine whether the design of the appliance is user-friendly enough, it is necessary to examine both its basic physical structure’s design, such as the microwave oven’s door and buttons and its navigation design, such as the menu.” In order to examine the basic physical structure design’s usability, we chose the two simplest but most important tasks for users: 
“open and close door” and “take out the tray and put it back.”
To examine the usability of the microwave oven’s navigation design, we chose one of the most important functions for cooking food:
set the oven temperature to a specific temperature (400 degrees).
Then we discussed which kinds of data should we collect and decided to collect three kinds of data:
1. The time spent for users to complete the specific task, which is the quantitive data, which we used this data to analyze the design’s efficiency.
2. The rating for difficulty (from 1 to 10) of completing the specific task, which is qualitative data, which we used it to analyze the design’s effectiveness.
3. The comments from users about the task, which is textual data, which we used it to analyze what improvements should be made to the design.
Then based on the three kinds of data, we designed our data collection form and wrote the usability scripts, which included the introduction and instructions for the usability test, to guide the actual test.

Our discussion
data collection sheets

Finally, we conducted our usability test on Lander Hall’s 7th floor on 2017, April 14th, 3:00 pm. We invited three participants to this usability test. None of them knew what they should do until they took the test, so their behavior during the test would represent their initial behaviors. During the test process, one of our team members acted as the moderator and read the instructions, while the other two people collected data. After analyzing the data, we made a presentation to introduce this usability test and analyzed the result.

The presentation of the usability test

Results summary:

After analyzing all of the participants, we noticed that all users felt that the first and second task were easy and had a higher level of satisfaction; however, all of them said the last task was hard and confused, and that is due to the microwave oven’s navigation design.


One of the most interesting and fascinating processes that we applied in this week’s Sprint is running the usability, because it gives designers direct feedback, a plan for improving their design, and people can always find surprising things when they run the usability test. For example, the designers of the Profile microwave oven tried to make the main menu as clear and concise as possible, and that can make users feel comfortable when they use the microwave oven. So, they let one button serve multiple functions, such as setting the time and temperature, and tried to come up with a summative name “convection.” However, when we ran the test, we found out that the user hardly understood what functions were included in the button, so they had to push all of the buttons and tried to find the right one. Designers usually don’t notice these kinds of flaws because, unlike new users, they are very familiar with the design, so they understand exactly what the interface is trying to communicate, but for first-time users, it may not be so clear. However, such problems can be figured out by conducting the actual usability test. This process is very interesting not only because it can expose the different thinking patterns between the user and designer, but it also gives the designer lots of meaningful feedback that they can use to refine their design.
One of the most interesting techniques I learned from this sprint is that moderators should repeat their participants’ answers back to them because it may prompt the participants to add more details about their answer and such details can be very meaningful for designers.

In the future:

After this sprint, I understand how powerful the usability test is. From my perspective, I believe all components of the product which are user-controlled should be evaluated with the usability test. For example, in the last blog, I said it is hard for me to make sure the navigation of the citizen app prototype is clear enough or not, and I now I think I should conduct a usability for my prototype to check that.
In the future, there are several things we need to improve in our usability test:
First, we should speak slower and louder next time. In this usability test, some of the participants asked us to repeat the questions sometimes because they didn’t fully understand what our moderator saying. This could have caused the participants to feel nervous and influenced their behavior during the test.
Second, we should invite more participants so that we can obtain more accurate data. For example, in our usability test, there was a huge variation in the amount of time participants took. Our last participant took just 45 secs to figure out how to set the oven to the right temperature, while the other two people took 90 secs and 2 mins and 45 secs to figured out the same thing. By increasing the sample size, we can reduce the effect of the the random error on our experiment.

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