4.1. Network Structure and Global Analysis
The network structure of the service project is illustrated in
Figure 1, generated using the Fruchterman-Reingold algorithm. This algorithm treats nodes as charged particles subject to two forces: Coulomb repulsion (between all nodes) and Hooke’s attraction (along edges). Under these forces, the layout stabilizes into an equilibrium state [
20]. Node sizes correspond to their degree centrality, while colors denote modularity-based communities (groups of nodes with shared characteristics, see
Table 2). The “After-School Program” network exhibits a decentralized multi-core structure, characterized by multiple high-centrality nodes rather than a single dominant hub. No isolated nodes were observed, indicating resource flows and communication rely on a system of interconnected key nodes. Tightly connected subgroups suggest collaboration clusters formed around shared goals or interests.
In social network analysis, network density serves as a core indicator for measuring the degree of interconnectedness among nodes. This metric reflects both the frequency of interactions and the overall cohesion within a service network. In the present study, a total of 39 nodes were involved in the network, which exhibited a density of 0.370 (see
Table 3). This indicates that only 37% of all possible connections were realized, revealing a relatively loose network structure. From a structural perspective, the network displays a distinct core–periphery pattern. Within this configuration, certain nodes—characterized by a high degree of connectivity—occupy central positions, thereby facilitating the concentrated flow of information and resources. In contrast, nodes situated at the periphery have fewer connections and thus play weaker and more limited roles within the network. This structural pattern illustrates the functional diversity of network members and their differentiated positions and roles within the overall system.
According to the distribution of distances between nodes (see
Table 4), 37.0% of node pairs are directly connected (distance = 1), suggesting a considerable proportion of immediate interactions. 62.7% of node pairs are connected via a second-degree path (distance = 2), indicating that most nodes are linked indirectly. Only 0.3% of node pairs are separated by a distance of three, implying that remote connections are rare. The average path length (APL) of the network is 1.632, meaning that, on average, information passes through approximately 1.632 intermediary nodes before reaching its target. This reflects the network’s relative compactness and efficiency in facilitating information flow. The network cohesion index is 0.685, suggesting that despite a somewhat loose structure, the network maintains strong internal cohesion. Meanwhile, the distance-weighted fragmentation index stands at 3.15, indicating that the network simultaneously exhibits a high degree of dispersion and hierarchical differentiation. This highlights the wide distribution and varied functional roles of members across the network.
4.2. Ego Network Analysis
Centrality measures the extent to which a participant is positioned between other nodes within a network, reflecting the degree of control an actor holds over network resources and their influence on interactions among others [
21,
22,
23]. In general, nodes with higher centrality possess greater control over information and resources within the network. These nodes often serve as key hubs for information dissemination and may act as potential leaders in guiding group behavior [
24].
Various methods are used to calculate centrality, with commonly applied metrics including degree centrality, closeness centrality, betweenness centrality, and eigenvector centrality [
25]. In this study, we focus on degree centrality and betweenness centrality. Degree centrality measures the number of direct connections a node has with others, while betweenness centrality evaluates the extent to which a node functions as an intermediary in the flow of information.
Nodes with high centrality often play crucial bridging roles within the network. They are not only capable of controlling the flow of information but also serve as effective regulators of interactions among other nodes. For instance, in social diffusion networks, individuals with high centrality often act as opinion leaders or decision-makers, exerting a dominant influence over group dynamics and information dissemination. However, it is important to note that an overreliance on central nodes may introduce potential vulnerabilities. The failure or removal of a highly central node can lead to significant disruptions in both the structure and function of the overall network [
26]. Therefore, in addition to analyzing centrality, it is essential to consider the network’s redundancy and backup mechanisms to enhance its robustness and stability. In the context of this study, this refers specifically to strengthening redundant connections within the network, thereby ensuring that other nodes can continue to maintain effective information flow even in the event of a central node failure.
4.2.1. Degree Centrality Analysis
Table 5 presents the degree centrality (D_C) and normalized degree centrality (ND_C) indices for all participants in the “After-School Program” network, calculated from the adjacency matrix.
Table 6 summarizes the descriptive statistics. Degree centrality quantifies the number of direct connections a node has, while normalized degree centrality (ND_C) represents the ratio of actual connections to the maximum possible connections, reflecting a node’s control over interactions and its centrality in resource allocation.
According to the descriptive results presented in
Table 6, the average degree of nodes within the network is 14.103, with a standard deviation of 3.671. This indicates that most nodes have a similar number of connections, concentrated within a relatively narrow range. The average normalized degree is 37.112, suggesting a generally balanced level of connectivity among nodes. However, a few nodes—such as node C1—exhibit notably higher degrees, indicating that a small number of core actors hold central positions within the network.
The network centralization is 27.45%, reflecting a moderately centralized core structure. This implies that the core nodes possess stronger capacities for resource control and information flow, which may enhance the overall efficiency of the network. The network heterogeneity is 2.74%, and the normalized heterogeneity is 0.18%, both of which are relatively low. This suggests that functional and role-based differences among nodes are limited, and that the network overall demonstrates a relatively balanced structural composition. Such a configuration facilitates collaboration among different types of actors, enabling tighter cooperation and the formation of effective service chains, thus strengthening the integration and complementarity of the service network.
An examination of degree centrality (see
Table 7) shows that core nodes such as C1, C2, and C3 have high degrees—24, 23, and 21, respectively—indicating their extensive connections within the network. These nodes likely play key roles in resource allocation, information dissemination, and decision support. In contrast, nodes with lower degrees—such as F1 and G5—can be identified as peripheral participants, with limited engagement in the network. These nodes are more likely to function as recipients or executors of information and services during program implementation. Nevertheless, the presence of multiple connections between peripheral and core nodes contributes to the redundancy of the network. Even though core nodes facilitate a large share of information flow, the distributed interactions across the network help mitigate the risk of overall system disruption in the event of a central node failure.
The network reveals a clear core–periphery structure formed primarily between project social workers (C1–C3) and community volunteers (D1–D6). Social workers act as central nodes, responsible for resource coordination, information transmission, and overall network management. In contrast, the community volunteer nodes occupy more peripheral positions, assuming supportive and operational roles, including the execution of specific services and dissemination of information at the grassroots level.
4.2.2. Betweenness Centrality Analysis
Table 7 presents the betweenness centrality (B_C) and normalized betweenness centrality (NB_C) indices for participants in the “After-School Program” network.
Table 8 summarizes descriptive statistics. Betweenness centrality measures the frequency with which a node acts as a bridge in mediating communication between other nodes, reflecting its influence over information flows [
27,
28,
29]. A higher value indicates greater control over critical pathways in the network [
30].
As shown in
Table 8, the mean betweenness centrality of nodes in the project network is 24.026, with a standard deviation of 17.938. This indicates that most nodes exhibit relatively low levels of betweenness centrality and that there is a notable degree of dispersion. The minimum value is 2.389 and the maximum is 81.401, suggesting that while a few nodes play crucial roles in information flow, the majority of nodes serve relatively weak intermediary functions within the network. The network centralization index is 4.19%, which reflects a broadly decentralized structure. Despite the existence of key nodes that facilitate information exchange, the low degree of centralization suggests that information flows through multiple pathways and is not overly reliant on a small subset of nodes. This decentralized configuration enhances the system’s robustness and resilience, making it well-suited for sustainable and efficient service delivery in grassroots community governance.
In the node-level analysis (see
Table 7), betweenness centrality is used to evaluate the importance of individual nodes and their capacity to control information flow. Node C2 exhibits the highest betweenness centrality at 81.401, with a normalized value of 5.790%, ranking first in the network. This indicates that C2 plays a critical bridging role, serving as a key conduit for information exchange among otherwise disconnected nodes. Nodes C1 and C3 follow closely with betweenness centrality scores of 75.141 and 64.294, respectively, confirming their pivotal roles in facilitating communication and coordination. Their high betweenness centrality makes them key actors in promoting collaboration and supporting the effective implementation of the project.
In contrast, node G22 has a moderate betweenness centrality of 16.13, with a normalized value of 1.147%. While not central, G22 still participates in multiple interactions, indicating a supportive role in facilitating information flow and resource exchange. Nodes associated with charitable resources—specifically F1, F2, and F3—display relatively low betweenness centrality scores. Notably, node F3 has the lowest value at 2.389, suggesting that it rarely serves as an intermediary in the flow of information. These nodes are likely located at the periphery of the network and perform more specialized or limited functions, maintaining fewer connections with other actors. Nonetheless, they may still play important roles in specific domains or targeted activities.
The network’s low centralization index further reflects a decentralized and flexible structure, which contributes to the overall resilience and adaptability of the project during implementation. This structural feature enhances the capacity of the network to function effectively in dynamic and complex grassroots governance contexts.
4.3. Grassroots Community Governance System Analysis
The “Five-Sector Linkage” (FSL) mechanism refers to a modern grassroots governance framework guided by Party leadership, in which the community residents’ committee (or village committee) plays an organizing role. The mechanism operates with the community as a platform, social organizations as carriers, social workers as key service providers, community volunteers as auxiliary forces, and philanthropic resources as supplementary support. To gain a deeper understanding of how this mechanism functions in practice, this study analyzes five key types of actors: the community, social organizations, social workers, community volunteers, and philanthropic resources. Using the “Four-Thirty Classroom” service project as a case example, the analysis highlights the synergistic effects among different actors within the FSL mechanism.
Table 9 and
Figure 2,
Figure 3,
Figure 4,
Figure 5 and
Figure 6 illustrate the specific interaction patterns and corresponding social network diagrams of these nodes.
In this project, the community serves as the core platform for governance and service delivery, carrying out the primary functions of community management and public service provision. Community actors (nodes A1 and A2) engage in close interactions with multiple other nodes, including social organizations, social workers, volunteers, and philanthropic entities. Through organizational structures such as the Party-Mass Service Center and the Residents’ Committee, the community connects with diverse social resources. Social Network Analysis (SNA) reveals that the significance of community nodes lies in their broad participation and influence across the network. For example, node A1 interacts with social organizations (B1), social workers (C1, C2, C3), community volunteers (D4, D5), NGOs (E1), philanthropic resources (F1, F2, F3), and participating children (e.g., G1), jointly advancing the project’s goals.
Social organizations represent a central force in driving service provision and fostering civic participation. The social organization node (B1) maintains frequent interactions with several other nodes, especially the community (A1, A2), social workers (C1, C2, C3), and community volunteers (D1, D2). Through project management and resource integration, social organizations play a critical role in both governance and service delivery systems within the project framework.
Social workers function as essential connectors among the community, social organizations, and residents. They are responsible for delivering services, coordinating resources, and mediating conflicts. In practice, social workers (C1, C2, C3) engage with all other nodes, forming an extensive and integrated social network. Their roles extend beyond service provision to include delivering professional support, conducting individual and group-level needs assessments, and performing targeted interventions within the community.
Community volunteers are indispensable actors in grassroots governance. By providing voluntary services, they help enhance community cohesion and collaboration. Volunteer nodes (D-series) are connected to all nodes except A2, F1, and F3. Specifically, volunteers participate in routine service tasks and activity coordination, assist social workers, and contribute to the implementation and development of community projects.
Philanthropic resources constitute a vital form of support within the community, participating primarily through financial and material contributions. Nodes F1, F2, and F3 maintain close interactions with the community (A1, A2), social organizations (B1), social workers (C1, C2, C3), and select volunteers (D1, D5). These philanthropic actors provide essential financial guarantees and material support for a wide range of community services. Their involvement ensures sufficient resources for services targeting specific groups such as the elderly and children, thereby enhancing the sustainability and quality of community governance and service provision.