Resumen: The aim of this article is to buid a Guide to the Analysis of Probability Textbook Lessons for secondary education (students aged 12-14), using the framework of Didactic Suitability. The facets, components and indicators of the didactic suitability construct are applied to categorize and organize didactic-mathematical knowledge on teaching and learning of probability in secondary education derived from research on the subject. The guide constitutes a systemic structure of descriptors (gradable and recognizable features in the textbook lesson) associated with the different components of partial suitability, which can facilitate the teacher's decision-making on how to use a textbook lesson in the classroom to optimise the instructional process. Idioma: Inglés DOI: 10.29333/iejme/17183 Año: 2025 Publicado en: International Electronic Journal of Mathematics Education 20, 4 (2025), em0858 [18 pp.] ISSN: 1306-3030 Financiación: info:eu-repo/grantAgreement/ES/AEI/PID2022-139748NB-I00 Financiación: info:eu-repo/grantAgreement/ES/DGA/S60-23R Tipo y forma: Article (Published version) Área (Departamento): Área Didáctica Matemática (Dpto. Matemáticas)