OXO Smart Shower Interface Prototype

Daniel Nguyen
Oct 6, 2019 · 6 min read

HCDE 451 Course Project


For my first assignment in HCDE 451: UX Prototyping Techniques, I was tasked to design a smart shower interface as if it were created by OXO. In case you aren’t familiar with OXO, here is a description from my assignment details:

The OXO brand is known for applying universal design to deliver well-designed, comfortable and easy to use tools for cooking and food preparation.

And the specifics of my assignment were to design a shower control interface that fit these requirements:

  • product controls and interface/display must fit within the dimensions of approximately 4 x 4 x 2 in volume
  • product weight is approximately .75 pounds, and should be able to be mounted on a wall
  • digital display will show settings such as temperature, water flow volume, valves (this could be used to control whether water comes out of the tub spout, the shower head, a handheld wand)
  • physical affordances and controls must be easy to use when visibility and dexterity are challenged by soapy hands, steamy showers, and absence of corrective lenses

My Design

Overall, my main goal for this product was to make it easy to use. I wanted to make it relatable to people when compared to existing shower controls, and I wanted to make it simple for use without sight and wet hands. My secondary goal was to OXO-fy the product.

Initial Prototype


  • Temperature controlled by a dial
  • Water Flow/Pressure controlled by a slider
  • Shower Mode controlled by a large button
  • Power controlled by a small button.
  • Digital screen showing temperature, water pressure, and shower mode
  • Adhesive on back for wall-mounting

Design Decisions

  • Different shaped and sized controls (slider, knob, and buttons) to facilitate usage without sight.
  • Temperature control is centered because it is the most used function
  • Braille and raised/depressed labels for accessibility and usage without sight
  • Minimal interface with large text for visibility and understanding at a glance

OXO-fied Prototype

Design Decisions

  • Rubberized controls for easy grips [aka OXO good grip tech]
  • StrongHold suction design to replace my standard 3M adhesive design
  • rounded corners to fit their design style

Final Prototype (After Testing and Classroom Critique)

Design Decisions

  • Changed the power button to be a small square to clearly be a button and have it be backlit when on to clearly show it’s on (implied)
  • Changed the volume of the shower mode button to make it more clear that it is not a knob
  • Kept the slider for water pressure. Asked participant if they considered having medium pressure and they agreed that a toggle did not allow for medium pressure, so they considered the slider decent.
  • Added hot and cold coloring on interface.
  • Improved the digital display to be less busy and easier to read.
From left to right: initial, oxo-fied, and final prototypes

My Design Process

Because I wanted to design something original, I decided to disregard the standard process of researching before brainstorming.


My first step in my process was to extract information from the requirements and focus on the features that I felt were necessary. I began sketching ideas for each feature separately and combined the best ideas for each feature as my initial product design.

My sketching process


With my initial design set, I created my initial prototype using foam, glue, and sticky notes.

My initial prototype: front (left) and back (right)

OXO-fying my design

After creating my first prototype, I modified its design to better fit OXO. I considered my initial design to be user-friendly and intuitive in its use, similar to OXO’s design style, but I wanted to establish it as a part of the OXO brand. I researched the OXO website and found that my shower control functions similarly to their StrongHold product line. So, I modified my design to incorporate their existing technology. Here’s a video on the tech.

OXO StrongHold Product Line
My second iteration of my prototype: front (left), back (middle), strong hold suction cup (right)

Usability Testing

Once my product was self-deemed OXO-certified, I tested it with someone. For my usability test, I only wanted to test the last two bullet points from the assignment requirements. Since I utilized OXO’s stronghold suction for wall mounting, I felt that it was unnecessary to modify that aspect of the design.

My usability testing tasks were to:

  • Turn on the shower. Set the temperature to your regular preferred shower setting and the water pressure to high.
  • Change the water to come out of the bathtub spout instead of the shower head.
  • Close your eyes, then set the temperature to the coldest setting and the water pressure to medium.
  • Turn off the shower with your eyes closed.
Video of Usability Testing

Iteration on Feedback

The last step I did was iterating on my design based on the results of my testing.

Feedback from testing showed that —

  • The power button was confusing because of the shape. Participant was unsure if it was a button, toggle, or slider. Also unsure if the system was on.
  • Digital screen was simple and easy to understand.
  • Participant was unsure of how to switch between shower modes. They felt that the button was too protruding and thought it was a knob.
  • Participant did not like the slider to control water pressure. They felt that it should be a binary button.

Overall, there were many hiccups with my design in terms of interacting with the buttons. However, the participant did feel that the design and layout of information was easy to read.


We also had an in-class critique session that identified a problem with the digital display being too busy and complex to read.

This was a great and fun assignment to work on. I really enjoyed thinking about and iterating through different prototypes.

I am pretty happy with my overall design. After testing, I felt that the design was mostly intuitive in terms of the user interface. However, testing did reveal the limitations of my prototype in that it was difficult for me to represent what I envisioned using materials such as modeling clay. I consider many of the mishaps with the user testing to be caused by my inexperience with modeling clay and not being able to shape it fully to how I wanted, for example, a button to look like.

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Daniel Nguyen

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Enjoying life one pixel at a time.

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Get smarter at building your thing. Follow to join The Startup’s +8 million monthly readers & +724K followers.

Daniel Nguyen

Written by

Enjoying life one pixel at a time.

The Startup

Get smarter at building your thing. Follow to join The Startup’s +8 million monthly readers & +724K followers.

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