Objective  Objective

In Georgia Tech, bike is one of the most frequent transportations. Every year, new students look for used bikes, newly graduates have to sell them. Our project is to help buyers to choose a high quality-price-ratio used bike quickly and help sellers to avoid spending lots of time looking for buyers.

MyRole  My Role

I participated throughout the research process of contextual inquiry, interviews and survey. I took charge of affinity diagram by collecting findings. I came up with two main design ideas which ended up as final solution. In design, I helped with sketching and interative prototype.

Duration  Time&Team

SecondBuy was done between September to December of 2017 with my awesome teammates: Lois, Angela and Akhil

Approach  Approach

We distributed a survey and conducted semi-structured interviews, contextual inquiries to identify problems that used-bike buyers and sellers meet. Based on the data gathered, we did affinity diagram to categorize collected data, whose findings are used to develop user personas.

These processes helped us understand our users better, and we identified 6 problems in their buying and selling experience of second-hand bikes. Considering their user scale and influence, we converged to 2 problems. Then we organized divergent brainstorming design sessions with 19 divergent design ideas. After doing a thorough analysis of their feasibility, creativity and to the biggest extent they can solve 2 main problems, we then converged to 2 design ideas.

The 2 ideas were presented to our class peers for feedback and evaluation by storyboards, wireframes. After multiple iterations, we finally came up with a system called SecondBuy with a mobile app and a physical bike station.

Process  Process


Survey  Survey

We distributed a survey with 82 responses to probe into GT students' likes and dislikes when they choose uses bikes, in this way we can get our feet wet in the topic and know what appropriate questions to ask in the following interviews and contextual inquiries.

Survey  Interview

We conducted 5 semi-structured interviews, which turned out to be very helpful when we can gather in-depth understanding of buyers and sellers.

Competitive Analysis  Competitive Analysis

Contextual Inquiry  Contextual Inquiry

StarterBike is located in CRC parking lot. It welcomed students each Friday afternoon.

We went there for contextual inquiries.


affinity diagram  Affinity Diagram

  • Pain points of Buyers
    - Lack of bike's Information
    - Lack of Trust to sellers & posted info
    - Want a lower price
    - Have trouble in delivery

  • Pain points of Sellers
    - Time-Consuming to list items
    - No access to buyers

UserRequirement  User Requirement

Instead of trying to solve every problem, we decided to put more efforts in solving the most important and urgent ones.


It turned out that 2 of them are the most important and have been waitting to be solved urgently: 1. Buyers' trust problem and 2. Sellers' time-consuming problem.

personas  Personas

We created 3 person types we felt needed considering different age, gender and cultural backgourds: 2 buyer personas and 1 seller persona.
Secondary personas about expert users can be created in the future.


brainstorming  Brainstorming

Idea convergence  Idea Convergence

After collecting the 19 ideas, we sorted each by their ability in solving problems on a chart with two main questions as two coordinates separtely. The higher one idea's value is in one coordinate, the better this idea can solve the problem the coordinate stands for.

Therefore, 1. Post a video, 2. Instant Buy and 3. Expert Community can solve the main two problems to the greatest extent.


information Architecture  Information Architecture

Sketches  Sketches

Sketches on whiteboard before moving on to Lo-Fi wireframe.

Lo-Fi  Lo-Fi wireframe

Mobile App - Homepage and Expert page

Web Page - Homepage and Instabuy

We decided to move on with the first Mobile app since nowadays people especially the young have been using cellphone which has advantage in size and accessibility. The preliminary user flow is as following.

Cognitive Walkthrough  Cognitive Walkthrough

I quickly made a Lo-Fi interaction prototype and we showed it to experts who have experiences in HCI field for cognitive walkthourgh when they gave us advices about what problems they think users might encounter within UI design, task flow and details of features.

Hi-Fi  Hi-Fi prototype

We moved to a Hi-Fi interaction prototype based on these feedbacks.


UsabilityTest  Usability test

We presented the Hi-Fi prorotype to 8 potential users, 3 sellers, 5 buyers to do usability test.

We have three parts in our usability testing: Tasks, post-each-task rating, post-all-task SUS and open-ended questions.

Iterative Design  Iterative Design

Based on feedbacks from usability test, we began to iterate our design.

Details  Hi-Fidelity Prototype details

Hi-Fi wireframes Details

My awesome team