Construction and analysis of verification protocols as diagnosis and recuperation tool

The verification of the students' acquisition at the end of a specific activity, at the conclusion of a study course or at the beginning of a new one, is a problem of great importance for teachers. We would like to present an experience regarding the construction of some entrance tests to upper secondary school on algebraic topics and the use of relative protocols as tools for diagnosis and as a basis for planning a didactic activity. Our report refers in particular to the topic of equations where we noted the main difficulties and a fracture between syntactical rules and internal semantics of operations. We would like to present our experience as an example of a work method(construction of a test, analysis and classification of the protocols, didactic intervention, assessment of the results) that in our opinion allows the utilizing of the moment of assessment as a starting point for learning improvement.