Tag : HCI Foundation Course Project         Date : Aug 2017 - Dec 2017

Category : UX Design, Retail Experience Design        Team :  Lois Zhao, Gaby Shangguan, Akhil Mohana


How can we improve second-hand retail process to make it trustworthy and efficient?

Buying or selling a used product is always a smart choice for on-campus students to save money. However, this process could be suffering. The quality is not guaranteed; the process is time-consuming. Especially for bike, it is in great need but very few students have examine knowledge.


SecondBuy is a project aiming to improve the used bikes retail experience for on-campus students.  Our group followed the user-centered design method in the design process.

Design Process

We conducted user research for both buyers and sellers. Then we identified two critical issues. After brainstorming and iterative design, we came up with the final design. Then, we evaluated our design by potential users.

My Role

I led research sessions and conducted interviews. After that, I created personas and designed the workflow of the system. I also helped with the high-fidelity prototype and conducted the evaluations. 


Buyer's Problems:

Time-consuming to check the quality of bikes. 

Lack of trust of the seller and product information.

Seller's Problems:

Time-consuming in negotiating and providing information on request.

Want to sell out the bike as soon as possible.

How can we make the retail less time-consuming and more trustful

Video & Close-up Photos

More details about the used bikes

Close-up Photo shots were taken by the expert, and a 360-degree video walkthrough to help users have a better understanding of the condition and look of the bike. 

Expert Checking

Objective reviews by expert

Users click on labels under "Something you may concern" to see examination result by experts. Experts' work was rated by previous buyers.

Quick Selling Process

Drop off the bike at bike station

After requesting to sell their bike on app, sellers will drop off the bike at on-campus transfer bike stations at any time they are available.


What was the problem? Why did it matter?


To identify user needs, we collected quantitative data by sending a survey to GT students. It helped us collect demographic data and broad users' opinions. The most important thing we found from the 82 responses was that majority of the users felt they were unsure about the quality of the bike posted online. Also, participants who tried to sell a bike reported that selling a used bike required a lot of effort negotiating with potential buyers.


Participants of the survey


Average budget for second-hand bike

$650 Bn

Second-hand market size



Want to try on the bike before buying


Want to sell their used bike


have the problem of time consuming

Contextual Inquiry

To better understand the context, we went to a second-hand bike shop: Starter bike, and conducted 8 contextual inquiries. We wanted to understand what they were thinking when making a buying or a selling decision. What problems did they have in the retail process? We took notes of users' behavior, how they examine the used bike and how much time did it cost.

Affinity Mapping

To better analyze our survey and interview's result, We decided to go through all the collected data and made an affinity mapping to categorize our findings. Some of the key insights were:

For buyers: 

  • Buyers had few bike knowledge. They had a hard time to make a decision especially when the bike information is insufficient.

  • Some buyers don't trust the bike's quality by simply looking at the posted photos.   

  • It was time-consuming to try on the bike at different seller's place and it was expensive to get it delivered.  


For sellers:

  • Some sellers are last minute seller that they want to sell the product as soon as possible. However, it took a lot of time to negotiate with potential buyers and provide more bike information on request.

  • It was troublesome to list detailed product information.


After understanding user's goals and pain points, I created personas to help synthesize the insights we'd uncovered. The user personas of our target group also helped us focus on specific problems to design solutions.

What we learnt

From our research and by doing affinity mapping and persona to analyze data, we uncovered some great insights of both buyers and sellers.

Buyers lack information about the bike and seller

Buyers are unsure whether the seller and the post of the bike are trustworthy. Most often, the posted information of the bike is incomplete and does not give sufficient information.

Buyers find it time-consuming to buy a basic bike

For second-hand bike buyers, they find comparing each bike’s quality, price and condition are time-consuming. It takes time to find a good quality bike.

Sellers spend a lot of time negotiating with potential buyers

For sellers, most of them want to sell out the bike as soon as possible but many buyers ask detail questions and negotiate on the price. Sellers also find it hard to arrange time for buyers to check the bikes.



How could research lead to design concepts?


We organized design brainstorming sessions for our key purchase experience problem areas we discovered in research: time-consuming, trusting problem and concerns about quality. In the first phase, we generated more than 30 different design ideas across 3 problem areas. We also realized that most trust solutions overlap with the solutions about the quality. I sorted each idea by what problem it solves and created the idea map. Our goal was to find out which of these ideas best solve the problems in question.

We love all our ideas, but which one should be carried on to next stage?


I advocated to use a rational way to justify our design ideas when there are different opinions in the group. More investigation with our target users is the key of decision. We decided to check the feasibility, functionality, creativity of different ideas with our target users. I listed top 3 ideas with the highest score among 30 ideas below. Our group then were convinced to move forward with these ideas.

#Challenge 1 How To Make Design Decisions?


We made 2 storyboards to illustrate the design ideas. One is about sellers and the expert community. Another is from the buyers' using part to check the quality of the bike. 

After converging on the ideas, we decided to mix and match the strengths of each concept to implement the final design. The main features are:

  • Expert reviews: Expert will examine the quality of the bike and provide an objective checklist. Buyers can also rate and write reviews for the expert. The bike listing also shows who reviewed the bike and the quality of the expert denoted by ratings by previous buyers of the expert reviewed product.


  • Video details and close up shots: On the product page of the bike will show 360 version of the bike and the test video of the bike. Users can see close up shots of the bike to get a sense of condition of the bike.


  • Pick up and drop off placeSecondBuy will install bike racks with smart locks at multiple locations all around campus. Sellers can drop off their bike at a specific place for their convenience and buyers can pick up the bike withQR code at any time.


Workflow, low-fi & hi-fi prototype, userflow


I synthesized these design concepts and created the workflow of the design solution.

Low-fi Prototype

When trying to buy a bike, users will look for detailed information. The wireframes show how the user sees video walk-arounds of the bike and close up images of different parts of the bike. This helps the user analyze for herself the condition of the bike, and assess quality/damages.


When the user is trying to sell a bike, he/she takes multiple video close-ups as instructed by the app. Each video is analyzed in the back-end to check for potential damages.


We then came up with the visual design of these solutions. Below is the flow of each screen.

Hi-fi Prototype

Buying a bike: We wanted to make sure the checkout process was really fast. From our contextual inquiry, we found that most buyers stuck to buying just 1 bike. This led us to get rid of the "Add to cart" option, and had the user directly go to making a payment. This helped save time considerably.

Rate the examine expert: Experts are members of the community who evaluate used bikes in return for a commission on the sale of the bike. The rating would help the buyer understand the condition of the bike.

Selling a bike: For our design, we tried to have the selling process as easy and quick as possible. The user only enters basic bike info. The rest of the info is filled in by the expert.


Usability testing, iteration, final design

For hi-fi prototype, we assigned four different but main tasks scenarios. We used the think-aloud protocol to know how users think about our design, and did usability testing with potential users, after letting them complete four task scenes, we asked them to do System Usability Scale that provides us with standardized testing results.



Based on the result of our evaluation we made change on our previous design.

Expert Rating: Some of the comments we heard frequently from participants were that they did not know the difference between the star rating for the expert and the product rating. Therefore, we decide to make the change in the rating part.

Editing Wishlist: A few participants did not understand the edit button was to modify items on the wishlist. We will change this now to have all the necessary information on each wishlist card.

Final Prototype

Try this prototype made by Axure.


What's my thought after the project?

Combinine business model with design: During our design process, we found to make the design reasonable we need to consider the business model first. For example, we need to consider how to pay the expert and how should the return policy work. Bad business model will also harm user experience. Motivated by this project, I took a business class: Analysis of emerging technology to gain better understanding of the market and more business sense.


Keep thinking and iterating: After finishing our main user flow. I kept reflecting on myself if the design meets our target users need. If there is anything missing? Then I realized that there are some edge cases I missed. I kept iterating on the design to handle the edge cases. However, in usability testing, users still posed some edge cases we have never thought about. This experience motivated me continuously thinking and iterating my design.

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