The three mechanisms of solution are related to the fact that to answer a question (solve a problem), one has to
understand the context that it stems from, which is characterised by how the phenomenon is represented, in what
language the intervention of this phenomenon is expressed and the applications that can be provided to these
interventions. The five types of problems and three resolution processes that Toulmin mentions give us ideas and
resources to design authentic problems aimed at learning that may trigger the process of modelisation in school
science because they present situations in which “good questions” can be raised, i.e., those that draw the student's
attention towards the main questions he or she must answer to understand “where the problem lies”. The following
paragraphs show that accounting for the five types of problems helps us review how problems tend to be presented.
According to Toulmin, the five types of problems that trigger change in subjects are related to the modelisation
process specific to the academic scientific activity, centred on the resolution of authentic and contextualised
problems. Some of these types of problems, which coincide with more traditional problems in science classes, raise
questions specific to the subject and topic under study: these are problem types 1, 2 and 3. Their relation to the
modelisation process is obvious. Type 1 problems are raised in the context of one of the subject’s theoretical
models, and the problematic “case”, which must be explained by solving the problem, is the “fact” that must be
regarded as a component of the model. Type 2 problems stress the argumentation that explains why a fact is part of
or justified in terms of the components of the model. Type 3 problems address the relationship between components
of the model, which in turn, can only be understood if the relevant relationships between various facts or
paradigmatic examples of the model are established. However, a large number of these problems (that we may call
“real” because they are related to episodes that students know, have experimented with and can explain) belong to
more than one subject simultaneously: these are type 4 and 5 problems. Type 4 problems combine concepts from
more than one subject and require an “ad hoc” perspective or Theoretical Model, which may result in providing
meaning to the question raised in the problem; these problems are interesting because they allow for developing
criteria to select adequate knowledge and critical thinking. Type 5 problems raise conflicts with the social use of
knowledge.