As part of the DIAGRAMS 2026 program we offer the following tutorials. The tutorials will take place Tuesday, August 25. Please click on the links to see the abstract and other information for each tutorial.
Heraldry as Information Graphics
Emanuel Jannasch (Dalhousie University)
Coats-of-arms were designed to deliver life and death information under conditions of high stress and poor visibility, and to bring a certain spectacle to the jousting pitch. What combat taught about visual ergonomics (and aesthetics) is still useful today. As families and states expanded through conquest, alliance, and intermarriage, heraldry developed to record complex genealogical and political information. While there are accents and arguably dialects, the language of heraldry functioned across a multilingual and largely illiterate Europe. The visual grammar used was encoded in a verbal form called Blazon, which is strictly enough structured to be implemented digitally. Participants in the Tutorial will be able to create coats of arms of increasing complexity using two different interactive online tools. Both the grammar of heraldry and the meanings it embodies should be of interest to anyone interested in visual thought. The tutorial will close with a different question, though: can heraldry provide the basis for a rich and highly iconic type of logical diagram?
Marlo Logical Boards
Marcos Bautista López Aznar (Universidad de Huelva)
This tutorial introduces the Marlo diagrammatic framework through direct manipulation of magnetic logical boards and a dedicated educational software suite. Participants will engage with the system as secondary school students do — working through syllogistic reasoning step by step using coloured tokens on physical boards — before exploring the digital implementation currently deployed in classroom settings.
The Marlo framework operationalizes syllogistic reasoning as a sequence of discrete, visually tractable operations: representing propositions as whole-part relations between subject and predicate, equalizing diagrams through conversion and transformation, summing compatible premises sharing a common middle term, and extracting conclusions from the resulting diagrammatic structure. Each operation is made explicit and manipulable, reducing dependence on logocentric formulas and making the inferential process visible at every stage.
The tutorial is structured in two one-hour blocks. In the first hour, participants will represent and solve a syllogism on 30×40 cm magnetic boards using coloured tokens. Each step will be demonstrated and discussed, with attention to recurring errors observed in both students and adult participants — errors that reveal systematic cognitive patterns of interest to researchers in diagrammatic reasoning, cognitive load, and logic education. In the second hour, participants will explore Marlo Suite Level 1, a modular application in which each logical operation is trained in isolation before integration into full syllogistic reasoning tasks. The software uses pictograms and fictional characters, making abstract structural relations perceptually salient and accessible from early secondary level (age 12 onwards).
The system has been in continuous curricular implementation at IES San Sebastián (Huelva, Spain) since the 2024–25 academic year, involving over 120 students across all secondary levels within an officially approved institutional programme. Five teachers from different subject areas participate in the project. This deployment provides an empirical basis for the pedagogical claims made in the tutorial and grounds the discussion in observable classroom outcomes rather than theoretical projections.
The tutorial will be of particular interest to Diagrams attendees working on the cognitive role of external diagrammatic representations; the design of diagram systems for non-expert users; the relationship between perceptual and inferential constraints in diagram use; and the educational applications of formal diagrammatic frameworks. The Marlo system offers a test case in which a formally grounded diagrammatic framework has been adapted for pedagogical use without sacrificing logical rigour — a balance that raises questions directly relevant to ongoing debates in the Diagrams community about the epistemic and cognitive status of diagrammatic reasoning.
No prior knowledge of the Marlo system is required. Participants are invited to bring a tablet or laptop for the software session, though projection-based demonstration will also be available.