Problem: Grocery shopping can challenging, especially when children are involved. Our research with parents revealed two common complaints: shopping trips take too long and finding/remembering everything one needs is a challenge.
Solution: Our team designed a two part solution: a mobile application that supports list creating and way-finding and an in-store LED light-based product location system. All combined, our system helps users plan ahead for a shopping trip, navigate the store more efficiently, and find everything they need.
My Role: UX Researcher & UX Designer
​​​​​​​Time Frame: Aug '18 - Dec '18 (five months)​​​​​​​
My Contributions
Research: Conducted an observational study at a local Walmart, completed a task analysis of a typical child-accompanied grocery shopping trip, co-designed a survey for parents, conducted three interviews with parents, participated in affinity mapping our data.
Design: Produced sketches and wireframes of one of our three initial design ideas, co-created a mind map of the ShopLight app, co-designed and prototyped the ShopLight app in Adobe XD.
Evaluation: Co-designed and conducted the A/B test of ShopLight, co-conducted the post-test questionnaire, contributed to the analysis of evaluation data​​​​​​​.​​​​​​​
Research Highlights
Observation & Task Analysis: After observing shoppers at local Walmarts, I produced a task analysis flow diagram that broke down the different phases of a child-accompanied shopping trip.​​​​​​​
Survey, Interviews, & Affinity Mapping: I co-designed a survey with the goal of discovering the common pain points and coping mechanisms associated with child-accompanied grocery shopping trips. I also conducted semi-structured interviews with parents. 
We affinity mapped our survey and interview data to identify patterns in our users' needs and experiences.
Design Highlights
Initial Concept Storyboards
Concept 1: A lighting system for product location that uses LED lighting and haptic feedback on the grocery cart to help users navigate the store and locate products on the shelves.
Concept 2: A cross platform shopping list that syncs three input methods (a digital paper-like surface, a mobile app, and a voice user interface) and provides an easy and flexible way to plan ahead and keep record of purchases.
Concept 3: A "Smart Cart" that (1) helps parents focus on shopping by engaging their children in the experience and (2) provides users the option of checking out at the cart, enabling them to skip the checkout lines.
Ultimate Two-Part Solution
- A mobile application that supports list generation and in-store way-finding
- An in-store light-based product location system. 
At home or on the go, a user can make a shopping list flexibly and easily. Once at the store, she opens the app, finds her list, and uses the app's navigational features to make her way through the store. Inside an aisle, her items automatically light up on the shelves, making it easy for her to retrieve them.

Mobile App Mind Map​​​​​​​
Mobile App Prototype (Adobe XD)
Full Prototype (App & LED Component)
We built the LED component prototype using an Arduino set and LED strips. In order to demonstrate how our combined system worked, we filmed a demo video at a local Walmart.
A/B Test of the ShopLight System: Participants completed a shopping list with and without the system in place. We counterbalanced the presentation order of the A and B conditions and measured the time it took the participants to complete each round. This test was intended to determine whether or not our design accomplished one of its core goals: making grocery shopping faster for users.
Post-Test Questionnaire: This was intended to qualitatively explore participants' experiences.
NASA Task Load Index (TLX) Assessment: Given after each condition, this method allowed us to compare the cognitive loads associated with the A and B conditions.
* The results of this study are specific to the subjects recruited throughout the five month project process and are not meant to be generalizable to the rest of the population.
Though our evaluation efforts were limited by time and resource constraints, our results were promising. For the average user in our study, ShopLight decreased shopping time and cognitive load, which were our two goals for the system.
In the A/B test, participants were 24.84 seconds faster (on average) at collecting their shopping list items when assisted by the ShopLight system.
The participants' NASA TLX scores showed a 47.11% average decrease in cognitive load when assisted by the ShopLight system.
Areas to Improve
We conducted the evaluation methods in a simulated store environment, which meant that typical environmental factors (sounds, lighting, the presence of other shoppers, etc.) were missing. Proper evaluation of the ShopLight system would need to take place in a real store.
Our light-based prototype was small in scale, with the capacity to highlight only four items. In order to properly evaluate the effectiveness of the ShopLight system, we would need to build and test a much larger prototype that spanned multiple grocery aisles.
Some participants claimed that the lights were distracting and over-stimulating. In a future iteration, it would be useful to test a version of the system in which users had to "click to find" an item.
Next Steps
Potential Applications
- Warehouse item location
- Online grocery ordering fulfillment
Potential Variations
- Replace the LED component with an AR product location system
- "Click to find" version, where only specified items illuminate