This dissertation research is a multidisciplinary inquiry into topicality, which involves an indepth examination of literatures and empirical data and an inductive development of a faceted typology (containing 227 fine-grained topical relevance relationships and 33 types of presentation relationship). This inquiry investigates a large variety of topical connections beyond topic matching, renders a closer look into the structure of a topic, achieves an enriched understanding of topicality and relevance, and induces a cohesive topic-oriented information architecture that is meaningful across topics and domains. The findings from the analysis contribute to the foundation work of information organization, intellectual access / information retrieval, and knowledge discovery.