Diagrammatic Use Cases in Vietnamese Upper-Secondary Educational Work: A Priority List for Vol 5 Example Selection

Document Engineering Volume 5 in the elixresearches program teaches Vietnamese 14+ learners to author diagrams as text using Mermaid, D2, and TikZ. The capabilitytrigger progression model from node H6.1 resolves the toolswitching question; the residual question this paper addresses is which diagrams to teach as worked exemplars, given that the curriculum has a fixed budget of approximately fifteen flagship examples and a long tail of incidental examples. This paper synthesises Tufte 2001 information-design principles, Bertin 1983 semiology of graphics, Novak and Cañas 2008 conceptmap pedagogy, Buzan 1974 mind-mapping, Larkin and Simon 1987 cognitive analysis of diagrams, Mayer 2009 multimedialearning principles, Hegarty 2011 visual-spatial-display design, the ISTE 2016 student standards on computational and visual fluency, the UNESCO 2018 ICT Competency Framework for Teachers, the Society for Science 2024–2025 International Science and Engineering Fair Rules, and the Vietnamese Ministry of Education and Training 2018 General Education Programme for Informatics, Mathematics, Natural Sciences, Literature, History, and Geography to derive a use-case enumeration and priority list. The enumeration covers twenty diagram use cases drawn from school project, science-fair, and capstone outputs across the Vietnamese upper-secondary curriculum. The substantive contribution is a twenty-row priority table assigning each use case to a tier (must-cover, should-cover, nice-to-have), an audience subset (school-project author, science-fair student, capstone presenter, math-olympiad student, competitive-programming-track learner), a tool recommendation consistent with the H6.1 progression model, a Vol 5 example-slot mapping, and a frequencyweight estimate derived from curriculum-document content analysis. Five worked use-case samples illustrate the must-cover tier. A Vol 5 example-selection mapping translates the priority table into the eleven-chapter exemplar inventory of the shipped first edition.