Definition and Criteria for Specific Learning Disabilities

Operational criteria for clinical diagnosis

For a difficulty in school performance to be considered clinically as a Specific Learning Difficulty (SLD), poor grades are not enough.

According to international diagnostic manuals, rigorous requirements must be met.

The main one is the discrepancy criterion, which evidences a significant gap between the student's intellectual capacity (his potential) and his actual performance in instrumental areas (reading, writing or arithmetic).

In other words, the student possesses average or superior intelligence, but his or her academic results do not correspond to it. In addition, the criteria of specificity and exclusion are applied.

The difficulty must be confined to a specific area (it is not a global delay) and cannot be explained by other primary causes, such as sensory deficits (blindness or deafness), intellectual disability, lack of schooling or extreme sociocultural factors.

Finally, the persistence criterion is key: the difficulty must be maintained for at least six months despite appropriate pedagogical interventions, which confirms its neurobiological and resistant nature.

Classification by severity and the RtI model

Learning difficulties are not binary (either you have them or you don't), but are distributed along a continuum of severity.

They are classified from Type I (School Problems), which are mild, transient and caused by external factors (such as bad habits), through Type II (Low School Performance), to Type III (AED), where the cause is intrinsic and neurobiological.

In the most severe degrees we find Type IV (ADHD) and Type V (Borderline Intellectual Disability). This classification makes it possible to adjust the intensity of support.

To manage this diversity without saturating clinical services, the Response to Intervention (RtI) model is used.

This preventive approach proposes to act before diagnosing. Quality teaching and group reinforcement (Level 1 and 2) are applied.