IntroductionQuick ResultBackgroundGoalUser Study IUser Study IIResultsDesign ConsiderationsConclusionAwards

Hit Around

UX Researcher, Engineer

Project Overview

Hit Around is an iteratively designed substitutional robot for immersive boxing. Users can play boxing in the virtual world and, at the same time, feel the haptic feedback from the real-world robot.  We collected users’ feedback from different exhibitions and user studies to improve the product.

My Contributions

  • I exhibited our product with our team in France, America, Japan, and Taiwan, with over 500+ users to experience it. As the team's UX researcher, I mainly collect user feedback. Based on this feedback, I can quickly propose new features and ideas to improve the product’s experience.
  • I conducted two user studies with 80 users, rigorously experimenting to explore the product's possibilities.
  • The studies proved that our product improved users’ immersion (16%), realism (22%), and enjoyment (16%).

Role

UX Researcher

Team

1 Hardware Designer
1 UX Researcher (me)
1 Unity Engineer

TImeframe

2023/07-2024/04
8 months

Tools

UnitySPSS
Max QDA
Quick Result
Background
With the advancement of technology, sports involving technology have become increasingly popular. Sports technology in entertainment enhances the experience of athletes and even viewers. For example, Ring Fit Adventure was a great success in this area. Nevertheless, the Olympic also held the first export series in 2023, which combined traditional sports and electronic sports. However, we found out that most VR fitness games only have viusla and audio feedback. In this case, we created a virtual boxing experience. In addition, not only the visual and audio feedback from the VR headset, we also created a substitutional robot for haptic feedback, allowing the users to have a more immersed experience.
Real-world experience of the product
Virtual-world scene of the product
Goal
Our product has been demonstrated in many places, receiving many users’ feedback. Based on their feedback, we had iteratively designed the structure and content.
However, we still need more rigorous experiments to prove the concept of the product. Hence, we conducted the following two user studies.
User Study I: Laboratory Experiment

To prove the concept of our product, avoid physical sickness but have positive immersion and enjoyment.

User Study II: Field Deployment

To explore how the general public feels about the product and know how our product interacts with the real world.

User Study I:
Laboratory Experiment

Goal

To prove the concept of our product, avoid physical sickness but have positive immersion and enjoyment.

Research Questions

To create such an immersive experience in extreme exertion, we first have to ensure that the users will not feel uncomfortable during the whole experience. Hence, we have to know that:
How will the users’ physical statement be while experiencing our product?
Previous research suggests that having haptic feedback in VR gives users more immersion and a better experience. Thus, we also want to confirm that:
How will the users’ immersion be while experiencing our product?
How will the users’ enjoyment be while experiencing our product?

Participants and Procedure

We recruited 24 users, with half of them having boxing experience while the others had not. Most of them have VR experience. The users will go through three conditions, which are VR boxing without the robot (NR), VR boxing with the fixed robot (FR), and VR boxing with the moving robot (MR).

Before experiencing each condition, the users have to fill out their pre-state of physical statement. After experiencing each condition, they will fill out their post-state of physical statement, immersion, and physical activity enjoyment by questionnaires.

Result and Discussion

We conducted a between-within study to determine their physical statement using the VRSQ questionnaire, immersion using the IPQ questionnaire, and physical activity enjoyment using the PACES-8 questionnaire.

  • How will the users’ physical statement be while experiencing our product?
  • How will the users’ physical statement be while experiencing our product?
  • How will the users’ physical statement be while experiencing our product?
The result shows that the users did not feel a sense of discomfort during the experiment. However, while the robot is moving, the users will feel significantly fatigued compared with no robot and fixed robot conditions. Next, the users also had better immersion with haptic. We can tell that MR is significantly higher than the NR condition, with General Presence (16%), Spatial Presence (10%), Involvement (17%), and Experienced Realism (22%). Last but not least, the users also enjoyed the haptic feedback condition significantly more than the no haptic feedback condition, improving 16% (MR compared with NR).

Key Findings → Next Step

  • Positive feedback from VR-experienced users → Understanding the general public's experience
    In our initial user study, we recruited participants familiar with VR to minimize interference during testing and gather focused feedback. While this approach provided valuable insights, commercializing the product requires understanding the target audience: the general public. Therefore, the next user study will focus on assessing how the general public interacts with and responds to the product.
User Study II:
Field Deployment

Goal

To explore how the general public feels about the product and know how our product interacts with the real world.

Hypothesis and Research Question

Based on the previous user study, we made the hypothesis that:
The users will be more stress-released after experiencing our product.
The users will be more delighted after experiencing our product.
The users will be more tired after experiencing our product.
We are also curious about how our product works in the real world. Hence, we are eager to know that:
How does the public, who rarely come into contact with such interactions, feel toward the experience?

Participants and Procedure

We recruited 69 users, aged 19 to 50, with 28 females and 41 males.

Before the experiment started, the users should fill out a prequestionnaire. They rated their feeling about the questions on a 1- 7-point Likert scale. We asked the users for their agreement about the following statements: (1) "I feel stressful right now," (2) "I feel delightful right now," and (3) "I feel tired right now." After three times of one-minute games, they will fill out their post-questionnaire with the same questions to know their statement. At the same time, we will go through quick interviews to find out their feelings.

Result and Discussion

The discussed aspect of the hypothesis is the three customized questions we asked in the questionnaire. The result shows that the hypothesis we made is supported. After the experience, the users released their stress and became more delighted and tired.

During the field deployment experiment, we discovered some environmental factors that could affect its performance. For example, common elements found in exercise spaces, such as spotlights and mirrors, affect the VR position’s precision. Reflection props and mirrors may lead the feature points to change when the position camera placement is different, making the environment light sources more complex. Others, such as the pit, friction, and tilt of the floor, were more difficult to solve. Solving these problems is an additional cost for the decorations, and working days are required. Therefore, an instruction manual on environmental factors is necessary to ensure successful field deployment.

Key Findings → Next Step

  • Prove of concept → Prove of business
    After conducting two user studies, we found that users provided positive feedback, and the product successfully achieved the initial concept we envisioned. Moving forward, the next step is to shift focus toward proving the business viability, ensuring the product can succeed in the market and meet commercial goals.
Results
Based on the two user studies, we analyzed the quantitative result as following.
Deisgn Considerations for Future
Besides from the quantitative results, we also found some design considerations for future design in immersive exertion interaction from the qualitative results.
  1. Aligning virtual and real-world areas in substitutional reality → Virtual object positioning
    During user studies, most participants felt their hands and the robot were well-aligned in the virtual space. However, a few, like P9 and P20, mentioned that while hand movement was precise and latency-free, the perceived distance was confusing. "Although the movement of my hand has no latency compared to the real world and is precisely positioned, the sense of distance still confused me a lot." While feedback on alignment was generally positive, designing for spatial consistency can improve realism.
    We propose refining object positioning—such as moving from a 2D to a 3D interface—to enhance depth perception and minimize alignment inconsistencies.
  2. Addressing the insecurity of exertion interaction in virtual reality →  Stronger positional Hints
    Physical exertion in VR can eliminate space limitations, but it’s essential to ensure user awareness of their surroundings to prevent collisions. Some users reported feeling insecure about colliding with real-world objects during intense VR activities.
    We suggest implementing corrective positional hints, like virtual boundaries or an arena, to help users feel more secured and stay within safe zones during immersive activities.
Conclusion
Our user studies revealed that the product allows users to be more immersed and enjoyed during VR boxing. We proved the concept of our design. On the other hand, we also find that in the future there are some fields for better design:
  1. Aligning virtual and real-world areas in substitutional reality
  2. Addressing the insecurity of exertion interaction in virtual reality
Our experiments primarily involved participants with less boxing experience. This has helped us imagine how immersive exertion interaction might develop for the public, and we have identified some design implications that could be addressed for future research.
Awards
  • Publish: Chang, K. N., Lin, C. H., Weng, Y. H., Chan, Y. H., Chen, P. H., Zeng, P. C., ... & Han, P. H. (2024). Metapunch X: Combing Multidisplay and Exertion Interaction for Watching and Playing E-sports in Multiverse. In ACM SIGGRAPH 2024 Immersive Pavilion (pp. 1-2).
  • Exhibition: 2023 Laval Virtual ReVolution Research- MovableBag+: Substitutional Robot for Immersive Boxing Training with Encountered-Type Haptic – Nomination.
  • Competition: 2023 TIE Award, Future Tech Award – Nominated
  • Competition: 2023 XR Creative Award – Student Group Award
  • Competition: 2023 Asia XR Golden Award – Best XR Technology Innovation Award 3rd

Other Works