Over the past decades, within research on giftedness, there has been a growing interest in twice-exceptionals students (2e), defined as a population who show, or have the potential to show, high performance or creative ability in one or more domains, and, at the same time, experience a disability or disorder. Twice-exceptionality requires a pedagogical gaze and an educational intervention that pays attention to the unique traits resulting from the co-occurrence of two or more seemingly antithetical conditions: the overlapping of exceptionalities leads to the inhibition of some traits, the exacerbation of others and the appearance of new ones. This actually makes complex the process of identification. In order to overcome this obstacle, various attempts are gradually emerging in different countries to develop tools that can facilitate this process. Within the inclusive school model that Italy boasts, it is imperative to pay attention to contextual variables and adopt a holistic approach in which this apparent opposite coexistence can find integration and mutual dialogue. As a result of a literature systematic review and a comparative study carried out on instruments available so far – integrating them due to a broader perspective of twice-exceptionality that takes into account the specific and unique traits in the profile of twice-exceptional students – the SiiDE scale is structured to facilitate their identification in the Italian context. The contribution presents the results of the analysing process of the twice-exceptionality construct and the definition of the indicators attributable to six different domains of functioning, as well as the short- and medium-term working plan aimed at highlighting the consistency indices of the items and defining the instrument.

Keywords: Twice-exceptionality, twice-exceptional students, unique traits, identification, scale.