This contribution proposes to study the problems faced by researchers who design simple and complex tasks intended to assess the knowledge and skills related to multimodal media literacy of secondary school students (13-15 years old) in the context of information search and production of a multimodal hypertext. These problems also lead to a reflection on the didactic modeling of reading and on the production of digital texts and their teaching contents, based on an attempt to reconstitute what poses or could pose a problem for the student. The questions raised in this article emerged in the context of an international collaborative research program (2018-2022) between four French-speaking countries (Belgium, Canada, France, and Switzerland) on the assessment of media literacy competencies of teenagers (13-15 years old) from each of these countries.