Week 5: Prototype Evaluation
This week, we first refined our 3D model in Unity by replacing the floor plan with a measurement grid and adding extra walls in the virtual space for participants to manipulate.
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| Final model for this week's prototype evaluation |
Our research questions remain unchanged from the previous week:
- What aspects of our design help collaborators establish common ground efficiently?
- How does our design differ from traditional mediums in terms of interactions?
- What elements of traditional mediums “map” well to a virtual environment?
- What challenges do clients face when using our solution?
We decided that for this round of evaluation, we might not be able to answer the first question since it requires synchronous communication during the design process to evaluate effectively, and our prototype currently does not support networking. So, we temporarily removed the question from this first round and focused on how our solution helps clients to better understand and communicate spatial concepts to designers.
For the evaluation, we focused on three major research goals:
- Understand how clients will use our solution to illustrate their ideas
- Identify possible challenges and the learning curve of our solution for further refinement
- Evaluate the core values that our solution brings to clients as well as its advantages and disadvantages
Evaluation Overview
Based on our research goals, we determined the prototype evaluation focus:
- Understand how changing viewpoints between small-scale and full-scale might facilitate clients’ spatial understanding.
- Understand how clients utilize and value object manipulation and 3D sketching functions for changing the spatial layout.
- Compare the client experience between 2D floor plans and 3D virtual space to identify advantages and disadvantages.
Evaluation Process
We designed a test protocol based on two conditions. Each session evaluated a single participant and took about one hour. Participants performed the same four tasks with both our solution and pen/paper. The order of conditions was counterbalanced. At the end, participants were interviewed about their experience using both mediums.
Evaluation Approach
Recruitment
After the model refinement, we started our recruitment of participants. To ensure the participant group could represent our target users which were project owners/investors, our criteria were that the participants should have a non-architecture background and have experience working with architects/interior designers or experience designing their home/workplace.
Scenario-based
The participants were described a scenario where they are planning a 1B1B one-floor home and just received a design concept from the architect.
Participants were asked to perform four tasks based on the scenario:
- Removing an extra room
- Separating the living room space
- Increasing the amount of natural lighting
- Further decoration of the whole space
Two conditions
Participants completed a series of tasks in both conditions (traditional floorplan & our solution) which were counterbalanced across participants. This allowed us to compare how their experiences and understanding differed between traditional markup methods and our solution.
User Testing
We recruited four participants based on a set of criteria that helped us approximate the target profile of non-expert clients that might be working with designers to plan a space. We also accounted for other confounding variables such as gender differences and VR experience.
- 4 participants (2 male, 2 female)
- Non-architecture background
- Has experience planning home or workplace
- Little to no previous VR experience
The testing took place at Startup Hall at the Univesity of Washington. We set up a room-scale VR system and ran one session on Friday afternoon and three sessions on Tuesday.
We used video cameras as our primary method of capture. In the VR task, we recorded the projected screen together with the participant due to the importance of body language in understanding their intentions. The audio was also recorded throughout each session since participants were asked to think aloud as they completed the tasks.
However, most participants expressed a desire for precise positioning and explicit measurement visualizations.
We used video cameras as our primary method of capture. In the VR task, we recorded the projected screen together with the participant due to the importance of body language in understanding their intentions. The audio was also recorded throughout each session since participants were asked to think aloud as they completed the tasks.
Findings and Implications
Key finding #1
Participants had more satisfying and reactive experiences with the manipulation function in virtual space because it provides instant feedback on the spatial change.Implication
The real-time feedback and visualization help users feel more satisfied with their design decisions, which could be a core value of our solution. We should consider the effect of gratification on client involvement.Key finding #2
Participants were more willing to experiment with different changes and specify the design when they are in VR compared to using pen and paper. Participants found that they easily got lost when sketching on paper due to the permanent nature of the medium.Implication
Our solution is valuable for encouraging user involvement due to the ease of experiencing changes without the need to commit to permanent modifications. We should continue to facilitate this kind of interaction and redesign the sketching function to reflect this value.Key finding #3
The flexibility of jumping between small-scale full-scale views increased participants’ spatial awareness. In particular, participants used the small-scale view for an overview of the spatial layout much like a traditional floor plan.Implication
The intuitiveness of the small-scale view transfers from traditional floor plans since it allows users to see the overview of the designed space. Perhaps we should emphasize this view over the full-scale and refine it to carry over more valuable aspects from floor plans.Key finding #4
The sense of measurement was more subjective to our participant group. In our prototype, they measured the size and distance (when manipulating objects) relative to other elements in the space instead of referring to the measurement grid.However, most participants expressed a desire for precise positioning and explicit measurement visualizations.
Implication
Clients considered our solution more as a tool to experience layout and design changes, but it is possible that designers have a different concern when looking at the space. We should investigate more on the need for precise measurement.Refinements
Based on user's behavior and their comments, we found several user experience and usability issues that we should take into consideration and go through a refinement.
User experience
- Participants found it challenging to sketch 3D concepts precisely to present their ideas.
- Participants found that it was hard for them to measure distance when moving walls and furniture.
- Participants could not tell whether the furniture was the right size
- Participants often made changes while in small-scale view. However, many reported dizziness or neck strain from looking down to perform tasks.
Based on the evaluation, we proposed following solutions to refine the user experience.
- We plan to provide an indicator or automated snap-to-surface function to help users with sketching.
- Dynamic measurements that will pop-out showing the exact distance while moving an object.
- When pointing to furniture, users can see the dimension information.
- We are lifting the small-scale model up based on participant height and making it adjustable so that they no longer need to keep looking down.
Usability
- Participants sometimes lost their sense of direction and location in VR, especially after teleportation.
- The controller button mapping was often difficult to remember, causing participants to trigger unintended actions.
- It was sometimes difficult for participants to make small manipulations with precision (e.g. to the walls and furniture).
Changes we plan to make to improve our prototype:
- Add reference objects or marks into the space to help participants locate themselves.
- Add labels to the virtual controller model for reference and streamline button interaction.
- Add a snapping function to help align objects to other objects automatically or tweak manipulation interaction.
Next Steps
Evaluate the common ground
We will present the virtual markup to designers via POV screen recordings of participant sessions and let them interpret the participants’ design intentions. We will also revisit video recordings and listen to participants’ thought processes so we can evaluate the accuracy of interpretation. This will help us determine if mutual understanding is reached and what parts of our solution were effective.
Refine the prototype
We will select the most significant usability problems relative to our topic and refine our prototype for the second round of testing.
Final Takeaways
Despite our initial assumptions, the 3D sketching function was not as intuitive as we thought. While most participants thought that the sketching tool was valuable for labeling and marking up the space, it was often challenging to use.
Another assumption was that our solution would provide an increased sense of scale. However, it was compromised by technical limitations in our prototype. It would be ideal to maximize the real-size feeling of the full-scale view by increasing the freedom for participants to walk around in the space so they would not have to rely on the teleport function quite as often.
Reflection
Our evaluation helped validate our design solution as participants expressed enthusiasm for the value of real-time 3D markup. Participants’ overall positive feedback on the manipulation function made us realize how instant visual feedback can help participants experiment with and understand spatial concepts to inform their decisions. While rough, our initial prototype was functional enough to be able to help us evaluate our research questions and reveal specific improvements for refinement. We are confident moving forward with our solution in the final weeks.




























