The Mint Challenge
A Microsoft Hacking Stem plant-monitoring kit that allows third graders to explore what impacts plant growth over time through data.
Helping networks of caregivers manage their loved ones medications with confidence.
The design challenge
The Microsoft Hacking Stem team develops affordable, project-based physical computing kits accompanied by lesson plans for classrooms that address STEM curriculum.

Our challenge was to develop a kit of our own that could contribute to the current library of Hacking Stem offerings. Our kits needed to cost less than $10 per student and facilitate learning related to specific Next Generation Science Standards.

Our Kit: The Mint Challenge

We developed The Mint Challenge, a hands-on plant monitoring kit for third graders aimed at helping students explore the question: what impacts plant growth over time?

Students assemble plant monitors using two mint plants, inexpensive sensors, and a pre-written codebase that turns sensor values into a data visualization dashboard. Using their student workbook, they track observations in the physical and digital system over three weeks, hypothesizing ways to improve mint plant growth in local community gardens.
microsoft expo AWARD
Best Documentation

How we got here

At a high level, our process consisted of a phase of research, ideation, and then two rounds of iteration through prototyping and testing.

Secondary research

The Big Question

We set out with a question: what makes a modern science classroom experience impactful for students? Also important, what makes a classroom experience successful in the eyes of teachers and administrators?

To investigate the answer, I first familiarized myself with the existing suite of Microsoft Hacking Stem Lesson Plans. I also explored Youtube channels and subreddits related to science experiments for kids as well as research happening in MIT Media Lab's Lifelong Kindergarten aiming to redefine creative learning. I synthesized my learnings into key observations that I used as grounding principles for ideation.

key observations

Great science projects...


Students should feel empowered to pursue their personal curiosities.

Embrace Hands-on

Assembling the tools with which they will experiment provides sense of ownership.


The topic at hand must be framed in an exciting way that inspires student engagement.


Brainstorming 10 Concepts

In response to our formative research, we ideated a collection of concepts that each aligned to a different NGSS standard. We sketched what these concepts might look like and described how they would be used by students.

Narrowing based on Feedback

We took our collection of ideated concepts to our Microsoft sponsor and the MHCI+D studio for feedback. Using a color-coded system of stickers, individuals could indicate whether they thought concepts were especially interesting and novel, successfully placed students as the driving leaders of experimentation, or too complicated to assemble.

After this session of outside critique, we had three concepts left as clear front-runners.

Brain Activity Simulator

A kit exploring how different parts of the brain activate for different types of work

Plant Monitoring Kit

A kit concept that helps third graders understand what plants need to thrive

Earth Rotation Simulator

An activity that teaches Earth's relationship to the sun and how that affects seasons

MORE down-selection

Discussing Concepts with Students

To help further narrow down to one concept, we took our ideas to potential users. We showed a group of seven third-graders video prototypes of our three concepts and let them interact with the props used in them before probing about their impressions.

I was curious which of our concepts aligned with the key observations regarding impactful science class experiments outlined earlier. Were the kids excited about the topics? Did the assembly of the experiments seem feasible? Did students feel they could explore their own curiosities with these projects?

My video prototype for a Plant Monitoring kit

The (brutally honest) students asked extremely clever questions about our prototypes, uncovering flaws and aspects of the ideas that were too abstract or boring. They also helped us to realize that we'd collectively made incorrect assumptions about the interests and knowledge level of third graders with the brain simulator and rotation simulator.

Whiteboard notes of our feedback from students. A was the Brain Simulator, B was the Earth Rotation Simulator
chosen concept

Moving Ahead with the Plant Monitoring Kit

In response to the student feedback, we realized that our plant monitoring kit concept had the most potential for inquiry-led experimentation and presented a topic area that excited students while not posing too many abstractions.

It was also clear that the kit concept needed iteration before prototyping - as it was presented in the video, it didn't provide much room for creative experimentation.

concept iteration

Meet The Mint Challenge

Before diving into prototyping, we discussed how the kit experience could promote inquiry-led experimentation for students to answer the question "what impacts plant growth over time?" Our Microsoft sponsor explained that providing an element of comparison in our experiment could help facilitate this, so we decided to iterate to a concept including two mint plants.

Using this system, students could manipulate each of their plants' environments differently and observe the impacts of their choices on plant growth. Additionally, attaching light, moisture, and temperature sensors to the plants and visualizing that data on a dashboard could provide a richer means for observation and analysis.

Why mint? Mint shows visual change quickly, a priority in our choice for a 3 week experiment.
1st round of prototyping & testing

Wizard of Oz

With a renewed vision for our kit, we built a behavioral prototype to explore it's look and feel, as well as its potential role in the classroom prior to beginning technical implementation. Using this prototype, we designed Wizard of Oz testing sessions to conduct with local teachers so that we could get feedback from teachers early on in our prototyping activities.

Our behavioral prototype, which we used in Wizard of Oz testing
Session outline for our Wizard of Oz tests with Teachers
1st round of Testing  

Learnings from Teachers


Framing the experiment through a narrative would increase student engagement


Our kit built well on the 1st and 2nd grade science curriculum on biology and plant topics


The long-term nature of our activity could inspire deeper personal investment and give students a better idea of how scientists conduct research


We needed to clarify the labels on our dashboard UI and readability could be improved through layout and use of color


To empower caregiving networks to share, access, and manage medicinal information together.


Brainstorming 90 Ideas

We each proposed around thirty concepts using design methods including 2x2's and Crazy 8's. We met with a Premera rep to discuss the viability and desirability of these concepts which helped us narrow to our twenty best candidates.

2nd round of prototyping & Testing  

More Making

This feedback from teachers provided us a clear path forward into technical implementation and creation of supportive written materials. We began many activities in parallel: development, creation of our instructions and lesson plan, and explorations of physical form.

Top: old dashboard UI. Bottom: new dashboard UI
user interface

Redesigning the Dashboard

In light of our testing feedback, we iterated on our original dashboard UI to improve readability. We also clarified the language surrounding the axes labels to increase interpretability of the historical sensor data graphs.

Fritzing Diagram and Arduino pic

Bringing the Kit to Life

Hacking Stem kits come with pre-written code. The expectation is that students need to assemble their sensors and Arduino, and the codebase will do the rest. This project format keeps assembly as a core priority in the user's experience, which provides an increased sense of ownership and investment.

I took lead with all physical computing efforts as well as writing our team's codebase using Arduino and Processing. Understanding that a third-grade user would have to carry out the assembly of their sensors and Arduino, I had to carefully consider the sequence of steps to ensure the smoothest user experience.

Preview of our instruction booklet
Communication Across stakeholders

Cohesive Instructions

Photo of our fully functioning kit
2nd round of testing

Testing with Student Users

We brought back a fully functioning prototype of our system including instruction materials and a paired student workbook to test with the same student users.


Each student wanted to analyze different aspects of the two plant system, so they desired flexibility in the student workbook.


Students were eager to take on the assembly of the six sensor set up, and perceived the instruction diagrams as sufficient guidance.


Watering the plants posed the threat of getting the Arduino microcontroller wet!


Kids wanted to eat the mint plants... Really badly?

iterating based on feedback

Improving The Mint Challenge Experience

The feedback we received from students helped us further improve the end-to-end experience of The Mint Challenge classroom kit. We iterated our physical form to include a protective shield around the Arduino in case students weren't careful when watering the plants. We also iterated the student workbook to be more flexible and personal toward individual students' curiosities.

Left: Arduino water shield. Right: a look at our iterated student workbook which facilitates observation sessions

To provide an experience users will remember fondly, we also needed to intentionally design its conclusion. The Peak-End rule explains that when humans remember experiences, they most often recall points of extreme emotion as well as the end of the experience.

Our testing revealed that the kids really wanted to eat the mint leaves. So, at the end of our instruction materials, we provided a recipe for minty lemonade. As a class, students will celebrate the end of this project harvesting their mint to make these drinks!

iterating based on feedback

Presenting at Microsoft

We presented our final kit concept to the Microsoft Hacking Stem team and other members of Microsoft Education at the conclusion of our project. The Mint Challenge won an award for Best Documentation, referring to our instruction materials created for both teachers and students.

Next Steps

While presenting at Microsoft, we were often asked where we would continue our efforts on improving The Mint Challenge if we had more time. We outlined two key areas for future work.

step 1

Pilot The Mint Challenge in a real classroom environment over a three week period

Since our kit would exist in a classroom environment for at least three weeks, it would've been especially valuable to test the experience with students over a similar timeframe.

Step 2

Try to bring more interactivity to the data visualization dashboard

With more time, I would've liked to explore a more interactive approach to the dashboard where students could adjust the axes of the graphed data as well as integrate the workbook check-ins into the digital platform. It would be interesting to see how these changes could impact the student experience.


This was one of my favorite projects to date. It solidified my passion for designing in the realm of education and learning. I personally discovered my passion for STEM around third grade, so I found it especially rewarding to spend time thinking about how to empower students to explore these topics.

Takeaway 2

I'm a maker!

The process of iteratively prototyping and testing with users was a blast for me. I feel in my element when I can leverage my technical background, writing, and storytelling skills to extract insights from users.

Takeaway 1

Balancing the needs of various stakeholders is challenging but crucial for designing impactful end-to-end experiences

At times it was a challenge to balance the needs of teachers, students, and Microsoft in the creation of our classroom kit.

Including multiple rounds of testing was
essential in making sure our materials supported each stakeholders' needs and ultimately provided a memorable experience for students.