This process log is a part of series from my HCDE 451: User Experience Prototyping Techniques class taken in Autumn 2023. This class exposes students to several prototyping techniques to solve several types of user experience design problems.
The subject of this assignment was to prototype a handheld device with both physical and digital controls mimicking OXO brand and design elements in a new product space.
Specifications
A shower control interface for a high-end, multi-feature valve and temperature control. Features include:
- 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)
Prototype
I started with some lo-fidelity sketches to bring my ideas to life. I mainly had two ideas in mind: an all-in-one control interface (Fig. 1) or a two-part control interface (Fig. 2).
I then prototyped these two concepts using paper and cardboard. I wanted to test two aspects of these prototypes: the mechanical aspect (how the knobs or discs turn) and the interface (where the buttons and displays were located). So, I chose to create a total of four prototypes for the two concepts.
Analysis
I then tested this prototype with my peers in the course and received feedback on its usability and desirability.
Usability
I asked my peer to test the functionality of both prototypes. Some things that I was testing were how well all the moving parts of each prototype worked, how intuitive were certain features such as turning the shower on/off, and whether the positioning of buttons and dials was simple and accessible to users of different handedness.
Desirability
I then asked my peer to either choose one of the prototypes or choose some of the features from each prototype. My peer instantly picked the All-in-one prototype. Her reasoning was that she liked having fewer screens and not having to look for a knob to alter the temperature or the water flow. Conversely, she liked the simplicity of having all features built into one interface with fewer screens.
She also mentioned that there was no value provided to her in precisely knowing the water pressure in psi because she would actually be able to “feel” it.
I also asked for feedback on improving the designs, which I discuss in the next section.
Design
Incorporating prototype testing and feedback, here’s the reasoning behind my design decisions:
All-in-one rotating dials
The all-in-one interface allows a simple and intuitive experience to the user by reducing the number of screens and displaying relevant information. The dials are big enough (4 inch and 2 inch diameter) to allow users to rotate them easily. This minimalistic design also caters to users of different handedness. A point of feedback on this design choice was to make the dials thicker and distanced from each other to enhance their affordance.
Simple display and buttons
Shower interfaces can be confusing, especially to new users. An uncomplicated shower system was paramount in designing a high-tech system. Therefore, much thought was put it into reducing the number of buttons that the user could interact with. For an example, I had an on/off button in my initial sketch. However, I soon realized that this was redundant since the shower could be turned on by rotating the pressure dial.
Consistency with existing systems
To make the interface intuitive, it was important to understand how shower interfaces currently worked. Following from the previous example, most showers turn on when the pressure is increased — there isn’t usually an on/off button. Making designs decisions consistent with how things are usually done was paramount in this process.
