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Willow Breast Pump

User Research | 2018

What's Willow?

Today, more than 80% of new mothers in the United States do breastfeeding, and 6 in every 10 new mothers are in the workforce. Traditionally breast pumps contain tubes and large parts that make it hectic and impossible for moms to easily pump everywhere. 

Willow is the first-ever, in-bra, wearable wireless breast pump that makes moms' lives and their breastfeeding experience more seamless. It's quiet and lightweight so moms can wear it anywhere at any time (even at work!) and easily pump. All it takes is a pump and a smartphone.

Project Goal

After launching the Breast Pump and the Mobile app, it was essential to learn more about the beta user experience, their challenges, and product gaps. A team of the researcher was formed to design and execute research studies, gather feedback, and turn them to actionable insights for the product development team.

My Role

User Research Engineer Intern


Breast pump and iOS interface


Oct 2017 - Mar 2018


Willow Pump


Process and Goals

Project Goal

As a research engineer intern, I have teamed up with a Product Manager, a Mechanical Design Engineer, and a QA Engineer to design and execute the research studies. Based on questions and the gaps that were already recognized by the team, it was decided to utilize three research methods to uncover areas of improvements and deeper dive into user behaviors:
  1.  Behavioral Research
  2. Exploratory Study
  3. Usability Testing
Below is the process that was taken to execute each method. Please read through this project to learn why such methods were chosen, how they were executed, and what did the team learn from each of them.

1- User Behavior Research

What we studied

After releasing the beta version of the Willow pump and the mobile application we were interested in the learning about real-world experience of users with the product.  We wanted to understand which parts of the user experience would be awesome, and which could use some improvement? Is the user clear about how the pump and the mobile app work?

How we did the research

We ran a qualitative in-field usability study with 10 early adopters. Our participants were moms who were nursing ranged in age from 28 to 40 and located in Northern California.

  • Prior to the study, we asked moms not to pump for at least past 3 hours before the research session so that they have enough milk for pumping during the study.

  • During the first part of the study, we asked moms to demonstrate how they interact with their pump and the accompanying app. We observed them as they assembled the pump and running a  rapid session.

  • In the second part of the study, we asked specific questions regarding some functionality.  For instance, we asked users to try different suction speeds (out of a total of 4) and say how they feel about them, and which speed they prefer (if any at all). This was important information since we were looking for any potential correlation between the milking speed and volume of produced milk.

What we learned

Most participants agreed that the Willow pump takes a little while to get used to since the bundle included an interface and a physical product. 70% of the users had confusion regarding the meaning of different LED colors. They were not able to immediately understand whether different LED colors signifying an error or were solely communicating information regarding the status of their current pumping session.

Some of the users said they wished the pump had certain features, like the ability to inform them they pump a certain volume or if they reached their pumping goal of the day. We noted this a potential feature to study and potentially implement in future releases.


It was very insightful to see how customers assemble and wear the pump in real-time. One of the main observations here was that more than half of the moms were wearing the pump only partially correct. Or they kept looking at the pump while using it which interrupted the ongoing session because of lack of sufficient latch. This valuable take-away made us rethink our training strategy, making sure we are providing the right level of information for the users. 

Behavioral Research
Expolatory Study

Exploratory Quantitative Study

What we studied

We wondered:

  • How often do moms use the pump and how fast or slow do they change phase in a milking session?

  • What is the average volume of milk in different users and what factors influence that? For example, does a higher or lower speed level result in more milk?

How we did the research

24 participants were given a diary to record and describe aspects of their lives that are relevant to nursing and pumping for a duration of 6 weeks. Diary studies are typically longitudinal and can only be done for data that is easily recorded by participants. So we used analytical data in addition to the diaries to map a bigger picture of moms pumping behavior.

What we learned

Willow pump initially supported four different speed levels. During the current and previous studies, we have learned that almost all of the users liked the middle speeds and couldn't tell the difference between the two. They also thought the other two speeds on the sides of the spectrum were either too fast or too slow for them.


From here, we looked at our cloud data from each user and recognized that in real life there's not much of a difference in the volume of produced milk with different speeds. 

This valuable discovery led us to reduce our speed options from four to one which ended up in a simpler user interface.

Another observation from the data was that we could identify users that were struggling with the pump — they were switching between milking phases too quickly or were receiving too many errors. This information helped us reaching out to them and offering training as needed.

Usability Testing

What we studied 

We wondered what users think about Willow mobile application and to

  • Identify problems in the design of the app

  • Uncover opportunities to improve

  • Learn about the target user’s behavior and preferences

How we did the research

We ran an in-site user testing study with seven participants where they were asked to perform specific tasks using the Willow iOS interface and think aloud while doing so. While the participant completed each task, we observed their behavior and listened for additional feedback and insights.

What we learned

Most participants admitted that the mobile app is easy to navigate overall. One of the features that some users explicitly brought up and admired was that the app alerts the user on their upcoming pumping schedule which helped them to build a more regular pumping habit and stay on track with their wellness goals.

Users shared with us they preferred to have more flexibility with the app including when they enter input about their baby, their pumping goals, etc. They required to go back and forth to make the right updates and didn't know why some input was even necessary to be added to their profile.​

Some users mentioned that they would need quick access to training videos, tips, and questions. This would help them to seamlessly find answers to any confusion they have almost instantly instead of reaching customer service or googling. In one of the scenarios, a couple of users mentioned that they did not know what to do when an error occurred. They needed more guidance on how to handle errors and "what to do to fix an error."

Usability Testing


After going through rounds of user research studies I think doing an early on participatory design would have been very insightful to ensure the user interface meets moms' needs and is usable for goals they would like to achieve. Observations from usability testing uncovered that users' mental models could have been captured and mapped more clearly.

In a participatory design process, participants will be given design elements or creative materials to construct their ideal experience in a way that expresses what matters to them most and why. Also, the card sorting method could be beneficial as it let users organize items into groups and assign categories to each group as makes sense to them.

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