Source-linked AI summary
Blocks: Collaborative and Persistent Augmented Reality Experiences
Anhong Guo, Ilter Canberk, Hannah Murphy, Andrés Monroy-Hernández, Rajan Vaish
TL;DR
Blocks addresses the limited support for collaborative, end-user AR creation by enabling persistent structures across time and space. The paper develops the mobile application and evaluates it through lab and field deployments with over 160 participants. Participants most enjoyed synchronous colocated collaboration, while location-independent structures generated more frequent participation.
Problem
Most AR experiences focus on consuming expert-created content, leaving limited support for collaborative creation by end users.
Method
The paper develops Blocks, a mobile application for co-creating persistent AR structures across synchronous or asynchronous, colocated or remote, and location-dependent or location-independent settings.
Results
Participants most enjoyed synchronous colocated collaboration, while they participated in more sessions when structures were location-independent.
Takeaways & Limitations
Persistent collaborative AR can support both enjoyable co-creation and frequent participation across different combinations of time and space.
Takeaways & Limitations
The lab used varying tasks, which increased result variance and made quantitative significance harder to establish; participants were also predominantly young technology-company employees.
Abstract
from arXiv · showhide
We introduce Blocks, a mobile application that enables people to co-create AR structures that persist in the physical environment. Using Blocks, end users can collaborate synchronously or asynchronously, whether they are colocated or remote. Additionally, the AR structures can be tied to a physical location or can be accessed from anywhere. We evaluated how people used Blocks through a series of lab and field deployment studies with over 160 participants, and explored the interplay between two collaborative dimensions: space and time. We found that participants preferred creating structures synchronously with colocated collaborators. Additionally, they were most active when they created structures that were not restricted by time or place. Unlike most of today's AR experiences, which focus on content consumption, this work outlines new design opportunities for persistent and collaborative AR experiences that empower anyone to collaborate and create AR content.
1 INTRODUCTION
Blocks addresses the gap between consumption-focused AR and collaborative end-user creation by supporting persistent structures across time and space. Lab and field studies examined how these dimensions shaped experience and participation.
- Motivation and contribution: Blocks enables end users to co-create persistent AR structures synchronously or asynchronously, either colocated or remote, and either tied to locations or free-floating.The application was designed to cover the collaborative dimensions of time and space in one tool.
- Evaluation: The studies included 24 lab participants, 68 field participants, and a later five-day deployment with 70 participants.The lab used three 15-minute sessions per pair, while the field study involved many short sessions averaging five minutes.
- Findings: Participants created diverse structures using more than 12,000 blocks in the lab and nearly 7,000 in the field.Examples included tables, castles, robots, and sailboats.
- Findings: Participants enjoyed synchronous colocated collaboration most, while location-independent structures produced more sessions throughout the day.Many participants also spent longer than required on creations and repeatedly engaged with Blocks.
- Contributions: The paper contributes Blocks, empirical findings on design dimensions affecting experience and participation, and recommendations for engaging persistent AR creation.These contributions support a vision of collaborative AR content creation by anyone.
2 RELATED WORK
Related work frames Blocks as a response to AR systems that are commonly consumption-centric, non-collaborative, or designed for experts. The paper examines collaborative authoring across location and time in one open-ended tool.
- AR content creation: Many AR applications let users consume or lightly interact with expert-created content rather than create AR content themselves.Existing creation systems also often target designers and expert creators.
- AR content creation: Blocks aims to lower the floor of AR creation for non-experts while retaining scope for complex and diverse structures.The authors compare the intended approach to building with LEGO bricks and describe a range from towers to sailboats.
- Collaborative AR: Only 10 of 161 AR studies in one meta-analysis focused on collaboration, underscoring the limited coverage of collaborative AR research.Related work also identifies design dimensions for collaborative AR applications.
- Collaborative AR: Prior collaborative AR research has examined selected modalities, but the literature has not fully explored the broader design landscape together.The paper positions its single application as a way to examine these choices comparatively.
- Persistent AR: Blocks extends block-based collaborative creation beyond game settings by allowing structures to persist at physical locations or outside a specific location.The work uses an open-ended creation environment rather than the constraints of a video game.
3 BLOCKS
Blocks is a mobile AR application built around cube-like blocks for creating persistent structures. Its features support approachable construction, collaboration, persistence, and location-dependent or location-independent experiences.
- Core features: Blocks uses mobile AR and voxel-like cubes so users can co-create structures that persist in the physical environment.The design draws on LEGO and Minecraft while targeting deployment through ubiquitous smartphones.
- Design process: Formative studies with 12 participants across seven sessions informed the app’s creation and collaboration tools.Participants thought aloud while building, and the interface was refined after each session.
- Core features: Users can add single or multiple blocks, choose colors and sizes, view usage status, undo their own additions, delete blocks, and access instructional hints.The interface also supports seeing collaborators’ cursors and online presence.
- Creation: The design follows low-floor, high-ceiling, and wide-walls principles by making placement easy while allowing unconstrained and diverse structures.Users can create anything from decorative forms to robots and dragons.
- Persistence and location: Blocks preserves block position, size, color, ownership, and other properties over time while supporting shared image markers for location dependence.Image markers maintain virtual structures’ orientation, rotation, and scale relative to the physical world across sessions.
- Collaboration: Blocks supports collaboration through synchronized user states, maps, blocks, cursors, and real-time event streaming.Users can see collaborators’ cursor size and color and the number of potential collaborators online.
4 LAB STUDY
The lab study evaluated Blocks as a creation and collaboration tool across colocated, remote, and asynchronous conditions. A within-subject design compared how location and timing shaped collaborative work.
- Study goals: The lab study examined tool effectiveness and differences between colocated and remote creation and collaboration.The study focused on participants’ experiences and participation across the design space.
- Participants: The study recruited 24 participants from a technology company across engineering, design, product, technical, and financial roles.Participants were predominantly young, with most aged 25 to 34.
- Study design: Pairs completed three counterbalanced 15-minute sessions using colocated-sync, remote-sync, and asynchronous collaboration modes.The modes varied whether partners shared a place and time while building the same or sequentially accessed structures.
- Study design: The conditions covered the possible combinations of collaboration across time and space within one application.They included same-place synchronous work, different-place synchronous work, and asynchronous work on partners’ structures.
- Procedure: Participants built a table, a robot, and a structure of their choice, with task order increasing difficulty and openness.Pairs could plan freely and stop or continue creating during each session.
- Measures: Researchers collected post-session ratings and open-ended responses, video recordings, creation and deletion logs, and participant notes.Measures included fun, engagement, and satisfaction with the resulting structures.
5 LAB STUDY RESULTS
The lab study showed that participants created diverse structures and generally enjoyed, engaged with, and felt connected while using Blocks. Collaboration mode shaped activity, awareness, creative choices, and enjoyment, with colocated synchronous collaboration preferred for experience quality.
- Collaborative Outcome: 465 blocks were added on average in open-ended sessions, exceeding robots sessions at 260 blocks.The session-goal effect was significant: F(2, 20) = 6.85, p = 0.005.
- Collaborative Process: Participants planned verbally, with gestures and sketches, but spent less planning time asynchronously than synchronously.Planning covered styles, shapes, colors, names, component sizes, and collaboration strategies.
- Collaborative Process: 454 blocks were added on average asynchronously, compared with 292 colocated-synchronously and 286 remotely-synchronously.The overall collaboration-mode effect was significant: F(2, 20) = 5.35, p = 0.014, although pairwise differences were not statistically significant.
- Collaborative Process: Colocated synchronous collaboration produced higher awareness of partners’ actions than remote-synchronous and asynchronous collaboration.Participants ranked colocated-sync significantly higher than both alternatives.
- Happiness, Creativity, and Closeness: Participants reported increased happiness, creativity, and closeness after using Blocks.Happiness rose from 5.17 to 5.79, creativity from 4.21 to 5.46, and IOS closeness from 3.04 to 4.5.
- Fun, Engagement, and Satisfaction: Colocated-sync, remote-sync, and async were ranked in that order for both fun and engagement.Participants strongly agreed that they had fun and felt engaged across all three conditions.
5.4 Summary of Lab Study Results
The lab study found that Blocks supported varied creation and positive collaborative experiences, with colocated synchronous collaboration preferred. Its controlled setting left naturalistic engagement and location effects insufficiently understood, motivating field deployment.
- Summary of Lab Study Results: Participants felt engaged, more creative, and closer to partners while creating varied structures with Blocks.They reported enjoying synchronous colocated collaboration the most and often worked longer than required.
- Summary of Lab Study Results: The lab setting left it unclear how participants would engage with Blocks in naturalistic settings.The study also lacked understanding of how AR-structure location affects creation and collaboration.
- Summary of Lab Study Results: The authors therefore deployed Blocks in the wild to study regular routines over longer time spans.The field deployment addressed questions that short lab sessions could not capture.
6 FIELD STUDY
The field study examined naturalistic engagement with Blocks and compared AR structures restricted to a location with structures accessible anywhere. Participants encountered the app through a three-day campus deployment.
- Goal and Method: The field study investigated naturalistic engagement and differences between location-dependent and location-independent AR structures.It recruited 68 participants over three days.
- Experimental Conditions: In the location-dependent condition, participants had to return to a poster’s location to access the AR structures.The deployment used visible posters in a lobby and cafeteria outdoor seating area.
- Procedure: Participants installed Blocks by scanning a poster code, explored a personal sandbox, and then entered a shared AR world.In the shared world, they viewed others’ creations and created structures for others to see.
- Measures: The field study’s descriptive statistics covered general results, creation, collaboration, and post-study ratings for both location scenarios.These results are summarized in Table 2.
7 FIELD STUDY RESULTS
The field study found that location shaped participation: location-independent access produced more sessions, while location-dependent structures prompted more blocks per session. Participants repeatedly used Blocks, enjoyed synchronous colocated collaboration, and incorporated the physical environment into their creations.
- Participation: 68 participants used Blocks in 222 sessions, adding 6,970 blocks across MyWorld and OurWorld.Average session duration was 5.1 minutes.
- Collaboration: Participants engaged in synchronous and asynchronous collaboration, with asynchronous sessions adding more blocks in both location scenarios.Location-dependent asynchronous collaboration added 1,232 blocks across 76 sessions, versus 490 blocks across 15 synchronous moments; location-independent asynchronous collaboration added 1,698 blocks across 115 sessions, versus 238 across 16 synchronous moments.
- User experience: Participants reported balanced benefits across location conditions, while synchronous colocated collaboration was especially enjoyable.Participants also rated Blocks as fun and engaging, with 74% using it more than once during the study.
- Physical environment: Physical environments influenced creations, but some participants felt constrained by the available space and their momentary surroundings.Participants built around desks, walkways, and fire pits, while small or cluttered spaces limited some creations.
- Shared creation: Participants found it fun and inspiring to build on others’ creations, and shared-world etiquette emerged around preserving perceived structures.Users often tried to make complementary or separate additions rather than obscure prior work.
- Location and activity: Location-independent access produced more sessions and repeated use, while location-dependent access produced more blocks per session.Location-dependent sessions averaged 58 blocks and 4.2 minutes; location-independent sessions averaged 35 blocks and 5.8 minutes.
8 EXTENDED DEPLOYMENT
A five-day interactive deployment extended Blocks into a naturalistic, cross-building installation supporting colocated and remote collaboration. Participants created diverse structures, returned repeatedly, and often spent more time using the application than required.
- Deployment activity: 70 participants interacted with Blocks during 447 sessions across the five-day deployment.Participants collectively spent 15.1 hours in the app and added 8,885 blocks.
- Creation: Participants created diverse structures, and 45% of sessions included at least one added block.The longest session lasted about 24 minutes and added 303 blocks to build a race car track.
- Engagement: 67% of participants used Blocks repeatedly, and survey respondents strongly agreed that they enjoyed collaborating with others at the same time.The repeated-use rate was similar to the 74% reported in the field study.
- Consistency: The extended deployment’s findings were consistent with the earlier lab and field studies.The installation supported colocated and remote collaboration through linked building-lobby displays and communication.
9 DISCUSSIONS AND DESIGN IMPLICATIONS
The discussion connects Blocks’ findings to design opportunities for collaborative AR. It emphasizes location-independent access, colocated synchronous creation, creative onboarding, coordination support, awareness, and tools that better connect virtual and physical environments.
- Design dimensions: The authors suggest combining location-independent access with colocated synchronous collaboration to support both higher usage and enjoyment.Their findings separately associate location independence with more engagement and colocated synchronous collaboration with preference.
- Creativity and bonding: Participants had fun, felt engaged and creative, and reported feeling closer to partners while using Blocks.The authors frame collaborative AR as a conduit for creativity and relationship-building through shared creation.
- Creative onboarding: Open-ended goals supported a wider variety of structures and more blocks, while thematic goals and personal sandboxes helped onboarding.The authors recommend a staged onboarding process that preserves creative freedom.
- Planning and communication: Planning and notes for future creators helped participants coordinate, motivating tools for planning and communicating suggestions.Participants often planned before creating and left guidance for later contributors.
- Awareness: Limited cursor representation made it difficult for remote collaborators to locate one another in 3D space.The authors suggest out-of-sight cursors or life-size avatars to improve multi-user awareness.
- Physical constraints: The LEGO-like interaction encouraged physical movement but made creation harder when structures exceeded users’ reach.Future tools could either simulate real-world affordances or manipulate physical constraints through grouped editing or advanced graphics.
- Virtual–physical integration: Participants used physical surroundings while creating but felt limited by Blocks’ tools for connecting virtual and physical worlds.The authors propose capturing scene objects and incorporating properties such as color, text font, and texture.
9.8 Improving Coordination and Motivation Support
The discussion identifies coordination and persistence-related constraints in Blocks. It highlights process losses during synchronous creation, possible vandalism and clutter from indefinite persistence, and the need for stronger coordination and content-management support.
- Coordination: Synchronous presence may create process losses, while participants added more blocks on average asynchronously.One participant reported reduced creativity when a more skilled partner was present.
- Persistence: Persistent structures raised concerns about vandalism, although no vandalism was observed during the studies.Participants left notes asking future creators not to remove or severely alter their work.
- Content management: Participants reported that the AR space became cluttered because structures persisted indefinitely.The authors suggest gradually removing content that is not actively maintained.
10 LIMITATIONS AND FUTURE WORK
The authors identify limitations in authorship support, lab-task comparability, and participant diversity, while proposing related future improvements.
- Remote collaboration: Remote collaboration could be facilitated by adding video and audio chat to the app.Participants could communicate through the lab separator or video conference during deployments.
- Authorship: The app did not distinguish contributions from different users, motivating future authorship, credit, and provenance features.Participants informally claimed structure areas or used initials to display authorship.
- Lab study design: Varying task types introduced result variance and made collaboration modes harder to assess quantitatively.The authors suggest structurally equivalent tasks for deeper comparisons.
- Participant population: Participants were predominantly young technology-company employees and early adopters, limiting population diversity.The authors plan deployments with a wider and more diverse population.
11 CONCLUSION
Blocks supported collaborative, persistent AR creation across space and time. Across studies, colocated synchronous collaboration was preferred, while location-independent use produced more frequent participation.
- Findings: Across studies with over 160 participants, people created diverse AR structures, enjoyed the experience, and often worked longer than required.The structures included varied creations shown in Figure 1.
- Findings: Participants enjoyed colocated synchronous collaboration most.This was the strongest preference pattern reported in the conclusion.
- Findings: Participants were most active in location-independent use, joining more sessions.This contrasts with their preference for colocated synchronous collaboration.
- Design implication: The findings suggest combining location-independent access with colocated synchronous experiences to support enjoyment and frequent usage.The conclusion presents this as a design implication for future collaborative AR experiences.