**3.3. The pedagogical instrument and cognitive structures**

The pedagogical instrument is designed to conduct the learner's strategies. An example of this conduct is to allow the learner to identify words by using in the first phase syntactic analysis of word sequences without ambiguous syntactic structures; the second phase is to let him/her learn the development of the syntactic structure of the various components starting from various clues (morpho-syntactic, morphological, sets of themes and pragmatic) and exactly establishing the coherence between inferred clauses starting from its knowledge bases in memory.

The cognitive model contains all the processes that are used by the learner to handle the interface and to learn for example: how to use the logic of reading: (left to right; top to bottom) and how to apply the logic of correspondence: (spoken word/ written word, spoken sentence/ written sentences). More generally, this model takes care of communications between the student and the system. In the microscopic approach, the instructional designer must specify in collaboration with the other design actors the knowledge that learners use by exploiting short-term memory and the knowledge which the agent proposes as being knowledge of the long-term memory. The other types of knowledge, "knowledge of the world" or rather everything that will be implicitly used by learners, are in fact considered as "practical knowledge".

An example of cognition amplification with the help instruments of the activity: Supposing we want to activate the semantic-spatial strategy of word recognition, the desired cognitive state would be represented as follows:

Desired cognitive state (action = activate word recognition strategy, knowledge = semanticspatial strategy, status = high (degree of mastery)).

Desired cognitive state (action = activate object-strategy, knowledge = problem solving started, status = mastery).

Desired cognitive state (action = activate cognitive competencies, knowledge = content analysis, status = very high (degree of mastery)).

Knowing that the status of the degree of mastery is very low, low, average, high, very high, using the help instrument may amplify the learner's skills which may also improve his/her metacognitive competencies. After the use of the help instrument by the learner, the system saves the news cognitive state of the learner in its knowledge bases as follows:

Cognitive state (metacognitive competencies, skill at using help, high (degree of mastery)).
