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GREENCROWD: Scalable Gamified Citizen Science Infrastructure

GREENCROWD is an open-source, modular, and gamified platform designed for geospatial citizen science campaigns. It was engineered to support large-scale participatory data collection while preserving a flexible architecture that can be reused across environmental, urban, and public health contexts.

At its core, GREENCROWD integrates GAME (Goals And Motivation Engine) to apply adaptive incentives such as points and leaderboards. The objective is not only to collect data, but to improve participation quality, reduce dropout, and sustain long-term engagement.

Why GREENCROWD matters

Citizen science platforms often prioritize social participation goals, but technical robustness is frequently under-evaluated. GREENCROWD addresses this gap by combining:

  1. Structured geospatial workflows for campaign execution.
  2. Gamification mechanisms for sustained participation.
  3. A reproducible load-testing framework for scalability validation.

The project positions technical scalability as a prerequisite for trustworthy citizen science at scale.

Data model and workflow

GREENCROWD organizes campaigns in four deterministic levels:

  1. Campaign: top-level unit for a citizen science initiative.
  2. Area: polygon-based geographic subdivisions of the campaign.
  3. Point of Interest (POI): concrete geospatial collection points inside each area.
  4. Task: the actionable data collection unit linked to each POI.

This hierarchy supports clear orchestration of data collection, assignment logic, and reporting.

Administrator and participant interfaces

Administrators can configure campaigns end-to-end through a management panel: define areas, create POIs, assign rewards, and publish task forms.

Task forms are built with SurveyJS and support:

  1. Conditional logic and dynamic question flows.
  2. Multiple field types (text, options, geolocation).
  3. Media upload capabilities for field observations.

Participants interact with campaigns through an interactive map interface powered by Leaflet and OpenStreetMap. When users enter the valid radius of a POI, the assigned task can be completed and submitted from mobile or desktop. Immediate feedback is shown through leaderboard positions, earned points, and activity trends.

Gamification and strategy layer

GAME integration provides the incentive logic behind GREENCROWD. Instead of static reward schemes, incentives can adapt to participation behavior and campaign needs. This enables:

  1. Better alignment between campaign goals and participant effort.
  2. Incentive redistribution strategies for underrepresented zones.
  3. More transparent and traceable scoring behavior.

This is especially relevant for spatial justice scenarios, where contribution patterns are often uneven across territories.

Privacy and compliance

GREENCROWD follows a privacy-by-design model:

  1. No personal data is stored in platform records.
  2. Identity management relies on anonymized IDs from external IAM services.
  3. The model helps reduce privacy risk and supports GDPR-aligned operation.

Technical evaluation and benchmarking

A full technical evaluation was executed using Locust load and stress tests across different cloud infrastructure profiles, including high-concurrency and constrained-resource scenarios.

Primary metrics included:

  1. Throughput
  2. Latency
  3. Error rate

The tests identified critical scalability thresholds and bottlenecks related to concurrency handling and caching behavior. A central conclusion is that scalability alone is necessary but not sufficient: long-term success depends on user acceptance, sustained adoption, and continued use over time.

Beyond the GREENCROWD case, the evaluation process itself contributes a reusable benchmarking method for citizen science platforms that need to demonstrate production viability.

Positioning in the citizen science ecosystem

Compared with platforms such as iNaturalist, eBird, GeoPick, MammalWeb, and domain-specific initiatives, GREENCROWD emphasizes cross-domain reuse through modular architecture and integrated adaptive gamification. The platform is intended to complement, not replace, existing initiatives by offering reusable infrastructure for participatory geospatial workflows.

Publication metadata

  1. Venue: 2025 10th International Conference on Smart and Sustainable Technologies (SpliTech)
  2. Conference dates: 16-20 June 2025
  3. Location: Bol and Split, Croatia
  4. Publisher: IEEE
  5. Website: https://greencrowd.app/
  6. IEEE Xplore date added: 30 July 2025
  7. Public link: https://greencrowd.app/

Current and future direction

A pilot scenario focuses on biodiversity-oriented spatial crowdsourcing in semi-urban areas. Participants contribute geolocated observations at predefined POIs. This setup provides a practical environment to jointly evaluate technical performance, usability, and the real contribution of adaptive gamification to sustained citizen participation.