Fig. 2

Note: Modularity scores of topic networks. Note: Modularity is a network value showing the strength of cohesive subgroups by comparing their intra-community ties to inter-community ties. High modularity may signify that a network has cohesive communities whose inter-community relations are relatively weaker, whereas low modularity indicates a network has stronger inter-community relations. The blue solid line represents modularity scores from topic networks that have 15 terms, whereas the red dotted line shows those from topic networks with 30 terms