Da Ronch, Mickael Gardes, Marie-Line Mili, Ismail 2026 This paper presents a tool for effectively assessing the potential of resources to promote mathematical activity in problem-solving within textbooks. This tool is based on a theoretical framework grounded in the concepts of didactic variables and research variables derived from the Theory of Didactical Situations (TDS). The tool was tested through the analysis, using triple-blind coding, of a large corpus of 312 problems from Cycle 2 (pupils aged 8 to 12), taken from the official textbook used in French-speaking Switzerland (MER). The calculation of Fleiss’s kappa coefficient combined with a Z-test showed that the criteria used to evaluate the resources in this corpus are reliable (κ ≈ 0.69, z ≈ 23.09,p-value <0.001). Furthermore, the validity of our tool was confirmed by functional a priori analyses carried out on prototypical problems belonging to each of the four problem classes identified in this corpus. These results therefore show that our tool is reliable and valid and can therefore be reused for other international research into problem-solving in textbooks. application/pdf https://fredi.hepvs.ch/global/documents/335284 https://fredi.hepvs.ch/documents/335284/files/sn-article.pdf eng info:eu-repo/semantics/openAccess CC BY Educational Studies in Mathematics. - 2026 Reliability of tool Validity of tool Problem solving Didactic and research variable Resource analysis Reliability and validity of a tool for analyzing resource potential for mathematical activity http://purl.org/coar/resource_type/c_816b