Participatability: A New Notion for Understanding People’s Acceptance of Participatory Systems

1. Introduction

Over the past decades, the significance of citizen participation has remained a central topic in academic discourse. Drawing on Arnstein’s seminal definition, citizen participation is essentially a strategic redistribution of power, actively engaging citizens in economic and political decision-making processes [1]. This multifaceted concept encompasses crucial activities such as information collection, communication, and data processing, which are fundamental for fostering inclusive governance [2].

The advent of advanced digital technology has profoundly revolutionized citizen participation, offering unprecedented opportunities for public engagement. Consequently, a plethora of innovative participatory projects have emerged globally, exemplifying the practical application of technology in promoting citizen involvement. The EQUATOR e-science project, as explored by Milton and Steed, harnessed mobile sensors and GPS devices to facilitate the collection of carbon dioxide measurements [3], thereby enabling citizens to contribute to environmental monitoring efforts. Similarly, the Common-Sense Project [4] introduced a participatory sensing system designed to monitor urban air quality, empowering individuals to play an active role in safeguarding public health [5]. Moreover, the OpenStreetMap (OSM) project has successfully crowdsourced geographic information from the public, demonstrating the collective potential of citizen contributions in mapping and spatial data development [6]. Recent studies have confirmed that digital participatory platforms significantly enhance the scale and sustainability of citizen-led data collection initiatives [7].

Participatory systems, constituting a discrete subset within the extensive domain of information systems, assume a pivotal role as technological enablers of the citizen participation process [8]. The magnitude of the participant cohort represents a critical determinant in assessing the efficacy of these systems. Notably, it wields a direct impact on both the volume and the comprehensiveness of the data aggregated. As such, a fundamental question emerges: to what extent can participatory systems efficaciously facilitate the recruitment of an adequate number of participants for a given project?

Within the field of information systems research, usability has been long acknowledged as a fundamental construct for discerning the factors that shape users’ acceptance of information systems. Nevertheless, participatory systems deviate markedly from traditional information systems in their underlying design principles. In contrast to conventional systems that place a premium on user satisfaction, participatory systems are not principally designed to cater to the immediate requirements of individual participants [9]. This fundamental divergence in design goals implies that the concept of usability has intrinsic limitations when it comes to explaining the motives driving users to engage with participatory systems.

This paper aims to introduce a novel concept for elucidating individuals’ acceptance of participatory systems. To achieve this objective, the study commences by meticulously examining the unique characteristics of participatory systems. Drawing upon a comprehensive synthesis of the definitions of system usability and the distinctive features of participatory systems, the concept of "participatability" is subsequently proposed. A series of well-defined criteria for evaluating "participatability" are systematically identified, with the overarching goal of providing a robust theoretical framework to explain how people accept participatory systems. To further validate the practical applicability of "participatability", subsequent case studies will be conducted to assess its effectiveness in the design and evaluation processes of participatory systems.

2. Defining Participatability

2.1. Why Participatability

Participatory systems are defined as information systems integrated into partici-patory projects, designed to facilitate citizen engagement and participation. The users of these systems are the participants of the corresponding participatory projects, and through the utilization of specific participatory systems, they can accomplish the goals of the projects. In contrast to traditional information systems, whose primary function is to satisfy the individual needs of users, participatory systems exhibit a unique characteristic. Specifically, the primary objective of a participatory system is to achieve the overarching goals of the participatory project, rather than merely fulfilling the immediate requirements of the system users. This fundamental distinction underscores the unique nature and purpose of participatory systems within the realm of information systems.

In the corpus of human-computer interaction research, extensive usability studies have unequivocally demonstrated that the functionality provision enabling users to accomplish their assigned tasks is a pivotal determinant in shaping user acceptance of information systems [10]. Nevertheless, participatory systems represent a radical departure from the conventional information system design paradigm. Instead of centering on fulfilling the idiosyncratic needs of individual users, these systems prioritize the overarching objectives of the participatory projects in which they are embedded. This fundamental shift in design orientation inherently challenges the applicability of traditional usability constructs for elucidating user acceptance in the context of participatory systems.

Recent studies further confirm that usability alone cannot explain sustained voluntary participation in citizen science and crowd-sourced data collection systems [11]. Voluntary participants care more about collective value, social impact, and motivational support rather than only individual task efficiency [12]. As a result, traditional usability theory fails to address the core challenge of participatory systems: attracting and retaining a sufficient number of contributors [8].

In light of this theoretical lacuna, the concept of “participatability” is herein introduced as a novel theoretical construct that extends the conventional usability framework. This extension is meticulously crafted to accommodate the unique onto-logical and epistemological characteristics of participatory systems. By introducing “participatability”, this research endeavors to establish a more nuanced and comprehensive theoretical framework, which is specifically tailored to the evaluation and interpretation of user acceptance within the distinctive domain of participatory systems. This new concept not only fills an important gap in the existing literature but also provides a solid theoretical foundation for future research and development in the field of participatory systems.

2.2. What is Participatability

The concept of participatability draws significant inspiration from system usability research. To develop a robust and comprehensive definition of participatability, a profound understanding of the underlying principles and evolving definitions of usability is imperative. This is because usability concepts serve as the cornerstone upon which the theoretical framework of participatability can be systematically constructed, enabling a more nuanced and contextually relevant interpretation of user engagement and interaction within systems.

The definitions of system usability have undergone a notable evolution over time. In the nascent stages of usability research, seminal works by Gould and Lewis [13] underscored the primacy of usefulness and effectiveness, laying the foundational groundwork for subsequent conceptualizations. ISO/IEC 9126:1991 further advanced this understanding by defining usability as a set of attributes encompassing the effort required for use and the individual assessment of such use by an explicit or implicit user group [14].

However, a significant paradigm shift occurred as the field matured, with an in-creasing emphasis on user experience, as highlighted by Nielsen [15]. ISO/IEC 9126-1:2000 reflected this transition by incorporating elements of effectiveness, productivity, safety, and satisfaction into its definition, emphasizing the software product’s ability to enable specified users to achieve designated goals within specified usage contexts [16]. Building on this, ISO/IEC 9241-11:2018 streamlined the definition, focusing on effectiveness, efficiency, and user satisfaction when a product is utilized by specific users to fulfill particular purposes in a given context [17].

Most recently, ISO/IEC 25010:2023 introduced a user-centric approach, defining usability as the level of effort exerted and satisfaction experienced by users during software interaction [18]. This standard prioritizes the quantification of user investment and gratification as key metrics for evaluating the usability quality of information systems, marking a significant departure from previous definitions and encapsulating the contemporary focus on user-oriented design principles.

While the definition of usability has witnessed substantial transformations over the past three decades, its fundamental essence persists, consistently anchored in the exploration of determinants that shape users’ acceptance of information systems. This enduring focus underscores the critical role of usability research in understanding and enhancing user-system interactions, regardless of the changing terminologies and conceptual frameworks.

In the domain of participatory systems research, participatability assumes a pivotal role analogous to that of usability in traditional system studies. This concept is closely associated with the acceptance of participatory systems by users and serves as a critical factor influencing system success. In this paper, a novel definition of participatability is proposed, which is derived by extending the established usability frame-work, specifically tailored to the distinctive features and requirements of participatory systems.

Specifically, participatability is defined as the inherent characteristics of participatory systems that enable the recruitment of an adequate number of participants, ensuring the completion of data collection tasks and the fulfillment of project requirements. The definition of participatability delineates two essential requisites that a participatory system must fulfill: First, the system should possess the capability to recruit a sufficient number of participants for a given participatory project. Second, it must facilitate participants (i.e., system users) in completing specific tasks (e.g., upload data) stipulated by the project.

Following the definition of participatability, the subsequent step is to conduct a participatability assessment. Drawing insights from usability research, the criteria for evaluating participatability are determined by analyzing factors influencing users’ acceptance of participatory systems. This approach ensures that the assessment frame-work aligns with the fundamental principles underpinning user-centered design, enabling a comprehensive and scientifically grounded evaluation of participatory systems’ effectiveness in engaging users and fulfilling project objectives.

3. Assessing Participatability

The development of assessment criteria for participatability follows a theoretically grounded approach analogous to the construction of the concept itself. This section first reviews established usability assessment criteria, then systematically derives and reinterprets dimensions tailored to the unique socio-technical nature of participatory systems. By extending the classic usability framework and integrating empirical in-sights from citizen science, crowdsourcing, and public participation platforms, a comprehensive set of evaluative criteria is established to quantify how well a system at-tracts, supports, and sustains voluntary participants. This structured approach ensures that the assessment framework is both conceptually consistent with usability foundations and contextually valid for participatory systems.

3.1. Criteria for Assessing Usability

The identification of usability assessment criteria is predicated on an in-depth investigation of factors influencing users’ acceptance of information systems. As previously discussed, three fundamental criteria have been established: effectiveness, efficiency, and satisfaction. Effectiveness pertains to the successful completion of tasks through system utilization; efficiency quantifies the time or effort expended in task completion; and satisfaction encompasses users’ subjective feelings and attitudes during system interaction.

Notably, multiple measurement approaches exist for each criterion, with well-established methodologies documented in seminal works [15,19]. These diverse methods provide researchers with flexibility in tailoring usability evaluations to specific contexts and objectives, ensuring comprehensive and context appropriate assessments of information systems. Effectiveness and efficiency measurements are typically derived from systematic observation of the entire information system usage process. Recent studies have re-fined core measurement metrics for these two criteria, focusing on task success rates, error frequencies, and resource consumption to capture objective user performance [20]. A systematic review of usability evaluation methods further confirms that user testing (UT) and heuristic evaluation (HE) are the most prevalent approaches, with standardized metrics ensuring consistency across different system types [21,22]. This variability underscores that, consistent with the fundamental tenets of usability definitions, the evaluation approach for a given information system must be customized to its specific application domain.

In contrast to the objective nature of effectiveness and efficiency measurements, satisfaction represents a subjective construct, posing significant challenges for quantification. As a result, standardized questionnaires have emerged as the most prevalent approach for assessing user satisfaction, with recent research prioritizing validated tools such as the System Usability Scale (SUS) [23], Usability Metric for User Experience (UMUX) [24], and Questionnaire for User Interaction Satisfaction (QUIS). These tools enable researchers to capture subjective user attitudes reliably, with modifications tailored to specific application scenarios. This methodological diversity high-lights the multifaceted nature of satisfaction and the need for context-specific measurement approaches to accurately capture users’ subjective experiences.

Despite its widespread application and theoretical maturity, the traditional usability framework exhibits inherent limitations when applied to participatory systems. Conventional usability criteria center on individual task performance, personal utility, and immediate user experience, which are insufficient to explain voluntary, collective, and public good oriented participation [11]. Usability does not address motivational drivers such as perceived social impact, value alignment, collective identity, or long term engagement retention [8]. More importantly, standard usability evaluations over-look critical issues unique to participatory systems, including privacy risks, data security, trust, contribution feedback, and flexible participation mechanisms, which have been empirically shown to determine whether sufficient participants can be recruited [28,29]. In this sense, relying solely on effectiveness, efficiency, and satisfaction fails to capture the core determinants of participatory system success. A revised and extended evaluation framework is therefore necessary to reflect the distinct socio-technical nature of participatory systems.

3.2. Criteria for Assessing Participatability

As a specialized category of information systems, participatory systems retain relevance to the three core dimensions of usability but require substantial reinterpretation to reflect collective participation and voluntary engagement. Empirical evidence from contemporary citizen science and crowdsourcing projects further indicates that critical factors influencing participant recruitment and retention lie beyond conventional usability measures. The assessment framework of participatability therefore integrates adapted usability-based dimensions and new context specific dimensions to form a comprehensive evaluation structure.

Effectiveness in Participatory Systems

In conventional information systems, effectiveness describes the extent to which users can accurately and completely achieve individual tasks. In participatory systems, however, users do not engage primarily to satisfy personal task demands. Instead, they contribute voluntarily based on perceptions of social value, practical relevance, and re-al-world problem-solving potential. Individuals are more willing to participate when they identify shared interests between their own values and the objectives of a project [30,31]. Opportunities to acquire new knowledge and practical experience also strengthen participation intentions [32]. Recent studies further confirm that perceived social impact and project significance are stronger predictors of sustained engagement than usability indicators alone.

This line of reasoning supports the development of a distinct evaluative dimension that reflects the unique effectiveness requirements of participatory systems. This dimension is referred to as Salience.

Efficiency in Participatory Systems

Efficiency in traditional systems emphasizes the reduction of time and effort in-vested in individual task completion. In participatory systems, however, participation often involves sequential tasks such as equipment setup, training completion, data upload, or content validation [33,34]. Complex or inflexible procedures create barriers that reduce overall participation rates. Work motivation theory suggests that individuals exhibit stronger positive motivation when they can autonomously choose the timing and manner of involvement [35]. Contemporary participatory platforms further demonstrate that modular, low barrier, and flexible design expands accessibility and encourages broader public involvement.

These observations indicate that efficiency in participatory systems extends beyond interface performance to emphasize procedural simplicity and structural flexibility. This dimension is referred to as Adaptability.

Satisfaction in Participatory Systems

Satisfaction in traditional information systems focuses on individual subjective experience and comfort during system interaction. In participatory systems, satisfaction arises not only from interface usability but also from value alignment, group be-longing, and identity congruence. Participants are more likely to engage when their personal values are consistent with the mission of a project [36,37]. Users differ widely in digital literacy, domain knowledge, and prior experience, leading to self-selection into projects that match their personal characteristics [38], as observed in the eMammal project [39] and the Great Pollinator Project [40]. When integrated with the Technology Acceptance Model [41] and Social Identity Theory [42], satisfaction in participatory systems reflects both instrumental fit and social identification.

This reconceptualization leads to a satisfaction derived dimension that emphasizes compatibility between system design and participant attributes. This dimension is referred to as Congruence.

Privacy and Trust in Participatory Systems

Traditional usability frameworks seldom treat privacy as a core assessment indicator, given their focus on individual task performance rather than sensitive data dis-closure. Participatory systems, however, frequently collect personal, spatial, or behavioral data from volunteers. Research indicates that perceived risks of information dis-closure strongly reduce willingness to participate [43]. Social exchange theory posits that individuals seek to maximize benefits and minimize costs in group activities [44]. In the context of participatory systems, privacy is often perceived as a cost to be incurred, which in turn directly influences whether individuals sustain long-term participation [45]. Recent studies further highlight transparent data policies, anonymization, encryption, and user control as essential conditions for building trust and sustaining participation in citizen science initiatives [46,47].

These insights establish privacy protection as an indispensable dimension unique to participatory systems. This dimension is referred to as Privacy Safeguarding.

Communication and Sustained Engagement

Usability evaluation emphasizes the quality of individual human computer inter-action but neglects ongoing communication between platforms and users. In participatory projects, however, sustained motivation relies heavily on clear feedback, contribution visibility, and perceived impact. Participants maintain higher engagement when they understand how their inputs advance project objectives [48]. Educational resources, skill building modules, and timely feedback further reinforce commitment [49,50]. Social psychological research indicates that positive reinforcement and meaningful interaction strongly predict repeated participation [51,52].

These findings highlight two-way communication and value-added interaction as critical components of successful participatory systems. This dimension is referred to as Interactive Engagement.

3.3. Synthetic Framework of Participatability Criteria

Based on theoretical reconstruction and empirical validation, this study defines five evaluative criteria of participatability:

• Salience: The system clearly communicates project significance, public value, and real-world impact.
• Adaptability: The system provides flexible, low effort, and autonomous participation pathways.
• Congruence: The system matches the skills, identity, values, and characteristics of its target users.
• Privacy Safeguarding: The system ensures data security, anonymity, transparency, and participant control.
• Interactive Engagement: The system delivers ongoing feedback, learning re-sources, and meaningful interaction.

These criteria collectively measure a system’s ability to attract sufficient voluntary participants, sustain engagement, and ensure reliable completion of collective data collection. This framework extends usability theory to address the unique socio-technical challenges of participatory systems and provides a rigorous, actionable basis for system design, evaluation, and improvement.

4. Implementing Participatability

Drawing on framework for multiple case study research [53], which supports robust cross-context validation and replication of findings, this section presents two complementary case studies to examine the validity, applicability, and explanatory power of participatability and its five assessment criteria in real-world participatory systems. The first case adopts an explanatory approach to evaluate a mature citizen science platform with more than 15 years of operational data, enabling longitudinal analysis of participatability and system performance. The second uses a descriptive and participatory design approach to investigate how participatability can be integrated during the system development phase to improve user acceptance and participation quality. Methods include participatory observation, secondary data analysis, questionnaire surveys, and semi-structured stakeholder interviews. Together, these two cases provide convergent evidence for the utility of participatability in both evaluating existing systems and guiding the design of new ones, strengthening the theoretical and practical contributions of this study.

4.1. Case Study 1: Project BudBurst

4.1.1. Project Background

Project BudBurst [54], established in 2007, is a long-running national citizen science initiative in the United States focused on climate change impacts on plant phenology. Participants observe and report key phenological events such as bud burst, first leaf, and flowering, which serve as sensitive biological indicators of climatic variation. Data are submitted through a dedicated web-based platform, generating a long-term, spatially distributed dataset for ecological and climate research. Given its scale, duration, and open data availability, Project BudBurst represents an ideal candidate for evaluating how participatability relates to sustained volunteer engagement and data productivity.

4.1.2. Participatability Assessment

Salience

Project BudBurst emphasizes the societal and scientific relevance of phenology monitoring through clear messaging on its website and across social media channels including Facebook, Flickr, and Twitter. The platform explicitly communicates the purpose, value, and real-world impact of citizen contributions, enabling volunteers to understand the significance of their participation. User-generated content functions further allow participants to share activities and observations, expanding outreach and reinforcing collective purpose. This emphasis on public value and scientific impact strongly supports recruitment and initial engagement.

Adaptability

The platform supports high adaptability by providing three distinct participation modes to match diverse user availability, commitment levels, and preferences:

• Regular Observation: For users pursuing continuous, long-term monitoring of specific plant species.
• Single Report: For casual or intermittent contributors submitting opportunistic observations.
• BudBurst Buddies: A youth-oriented program with age-appropriate tasks and educational materials.

This modular design lowers barriers to entry, accommodates heterogeneous users, and supports sustained participation by aligning system requirements with user capacity.

Congruence

The system is designed to align with the identity, knowledge level, and motivational characteristics of its target users. It uses narrative and visual content to attract younger participants, provides educational resources about native plant species, and shares annual research outcomes to reinforce shared values among environmentally engaged volunteers. These features foster group identification, strengthen perceived fit between individual interests and project goals, and support long-term retention.

Privacy Safeguarding

Project BudBurst maintains strict participant-centered privacy policies. All personally identifiable information is kept confidential and never shared with third par-ties. Publicly available data are fully anonymized, with no linkages between observation records and individual identities. These measures reduce privacy concerns, build trust, and support voluntary data disclosure in citizen science contexts.

Interactive Engagement

The platform provides comprehensive supporting materials, including participation guidelines, project reports, and open datasets to maintain transparency and in-form volunteers. However, the system lacks personalized feedback mechanisms that communicate how individual contributions directly influence project outcomes. Strengthening individualized feedback would likely further enhance perceived value, psychological satisfaction, and continuous engagement.

4.1.3. system performance result

To validate the practical relevance of participatability, this study uses two core indicators of participatory system success:

• total volume of collected data
• size and retention of the participant population

Longitudinal analysis of Project BudBurst data from 2007 to 2025 reveals substantial growth in both scale and sustainability (Table 1). Annual data submissions start-ed at only 920 records in 2007, rose to a peak in 2008, and then stabilized during the initial five-year period. From 2007 to 2011, the system averaged 2,759.4 records per year. Between 2012 and 2025, this average surged to 9,274 records per year, representing an increase of more than 300%.

Over the study period, the total number of participants increased from 12,837 (2007–2011) to 34,680 (through 2025). Average contributions per person rose from 1.07 entries to 3.74 entries, an increase of approximately 249.5%. This trend indicates a significant shift from one-time participation to sustained, repeated engagement, strongly consistent with the high level of participatability embedded in the system’s design.

These results demonstrate that systems supported by strong participatability characteristics can achieve substantial improvements in participant recruitment, retention, and data productivity. The longitudinal evidence from Project BudBurst validates that participatability is closely associated with the long-term success of participatory systems.

4.2. Case Study 2: Neighborhood Planning in University Campus

4.2.1. Project Background

In 2024, HeNan Vocational College of Applied Technology launched the “Design Your Campus” initiative to support student-led planning for new learning and living facilities. To enable broad participation, a web-based participatory planning system was developed that allows students to propose, visualize, and submit campus layout designs. This case examines how participatability can be integrated during system de-sign to improve user acceptance and participation quality.

4.2.2. Group Consultation Session

A participatory design approach was used to elicit user requirements. A consultation session with 67 students included four structured stages:

• Project overview and objectives
• Explanation of core system tasks
• Collection of user requirements and design expectations
• Open Q&A with development team members

This process ensured that user needs were systematically incorporated and that participants perceived ownership over the system design.

4.2.3. Questionnaire

A questionnaire was developed based on the five participatability criteria to measure user perceptions and acceptance. The instrument included 15 items rated on a 5-point Likert scale (1 = strongly disagree, 5 = strongly agree). Mean scores were used to evaluate the perceived importance of each dimension(Table 2).

4.2.4. Results

Student feedback from the consultation fell into two major categories:

• Technical usability: Interface simplicity, training support, map interaction, and visual design.
• Participation governance: How contributions would be processed, evaluated, and translated into actual planning decisions.

The prominence of the second category confirms that participatability-related concerns are central to user acceptance, distinct from but equally important as conventional usability. A total of 341 valid questionnaire responses were collected. As shown in Table 3, all 15 items achieved mean scores above 3.5, with standard deviations below 1.0, indicating strong consensus and high perceived importance of all five participatability criteria.

Following development, the system was launched and received 317 valid design proposals. Notably, 97% of contributors had participated in the consultation, and 89% had completed the questionnaire, indicating strong continuity and acceptance. These results confirm that integrating participatability into system design significantly improves user willingness to engage and supports effective participation.

4.3. Discussion

The primary objective of these case studies is to verify the validity and applicability of the proposed participatability construct and its five assessment criteria, and to further illustrate why such a new concept is indispensable for research and practice in participatory systems. The following discussions summarize the findings from each case and synthesize key theoretical and practical implications.

As a long-running citizen science platform with extensive longitudinal operation-al data, Case Study 1 (Project BudBurst) provides empirical evidence for the explanatory power of participatability in evaluating mature participatory systems. The assessment shows that the platform’s strong performance in participant recruitment, data accumulation, and long-term engagement can be consistently explained by the five participatability criteria: salience, adaptability, congruence, privacy safeguarding, and interactive engagement. The observed growth in participant numbers, data volume, and individual contribution frequency directly reflects the positive effects of high participatability design. This case confirms that the proposed criteria can effectively identify the strengths and weaknesses of a participatory system and reveal the under-lying mechanisms that drive sustained public engagement.

Case Study 2 (campus neighborhood planning) examines participatability from a system design perspective, in which the five criteria were intentionally applied during early-stage development. User feedback from consultation sessions and questionnaire results demonstrates that participants placed substantial importance on all dimensions of participatability, with scores indicating strong consensus across the sample. Users cared significantly about the value of participation, flexible ways to contribute, identity alignment, privacy protection, and feedback on their inputs—factors beyond conventional usability. The high participation rate and effective contribution behavior after system launch further validate that participatability can serve as a practical and actionable design framework, rather than only a retrospective evaluation tool.

Taken together, the two case studies converge to support the necessity and uniqueness of participatability in the field of participatory system research. Traditional usability focuses on individual task completion and personal experience, which is in-sufficient to explain or guide voluntary, collective, and public-good-oriented participation. In contrast, participatability captures the core socio-technical characteristics of participatory systems by emphasizing collective value, motivational support, trust building, and sustained engagement. The consistent findings across different contexts confirm that the five criteria form a comprehensive, stable, and generalizable frame-work for understanding user acceptance.

This research demonstrates that participatability is not merely an extension of usability but a necessary and distinct theoretical construct for participatory systems. It addresses a critical research gap by providing a systematic and empirically supported basis for both evaluating existing systems and designing new ones. By highlighting the importance of the proposed criteria, this study strengthens the theoretical foundation of participatory system research and offers practical guidance for improving participant attraction, retention, and overall system effectiveness in real-world participatory projects.

5. Summary

This study systematically proposes and validates the novel concept of participatability as a dedicated theoretical and evaluative framework for participatory systems. By recognizing the fundamental differences between participatory systems and tradition-al information systems, this research addresses a critical theoretical gap in which conventional usability criteria fail to explain voluntary collective participation, public engagement motivation, and long-term participant retention. The core contributions of this study can be summarized at theoretical, methodological, and practical levels.

Theoretically, this study establishes participatability as a distinct and necessary construct that extends and complements traditional usability. It clarifies the unique socio-technical characteristics of participatory systems, which prioritize collective value, public good, and sustained engagement rather than individual task performance alone. By defining and validating a five-dimensional evaluative framework consisting of salience, adaptability, congruence, privacy safeguarding, and interactive engagement, this study provides a rigorous, cohesive, and empirically grounded theoretical foundation for understanding user acceptance in participatory systems. This new framework enriches the theoretical landscape of citizen science, crowdsourcing, and public participation systems, and responds to the growing demand for con-text-appropriate theories in digital and data-driven participatory governance.

Methodologically, this study develops a systematic and operable set of assessment criteria for participatability. By reinterpreting usability dimensions and integrating new context-specific factors derived from recent empirical research, the proposed criteria enable consistent, comparable, and comprehensive evaluation of participatory systems across citizen science, urban planning, environmental monitoring, and public governance domains. The two complementary case studies further verify the reliability, applicability, and explanatory power of the framework, supporting its use in both retrospective system evaluation and prospective system design. This methodological contribution enables future researchers to measure, compare, and improve participation effectiveness in a more structured and evidence-based manner.

Practically, this study offers actionable guidance for developers, managers, and policymakers engaged in participatory system design and governance. The findings demonstrate that systems incorporating high levels of participatability attract more participants, achieve higher data volume and quality, and sustain longer-term engagement. By prioritizing project salience, flexible participation pathways, user identity congruence, privacy protection, and interactive feedback, practitioners can design more inclusive, trustworthy, and effective participatory systems. The validated framework therefore serves as a practical blueprint for enhancing participation success in citizen science projects, open data platforms, collaborative governance initiatives, and public-facing information systems.

In conclusion, this study confirms that participatability is indispensable to the study and practice of participatory systems. By shifting the analytical focus from individual usability to collective participation capacity, this research opens new directions for academic inquiry and supports more effective and sustainable participatory systems in the digital era.