The IDS-2 has been standardized on children and adolescents aged 5:0 to 20:11 years in:
Development is in progress in the United States, Czech, Danish, Finnish, French, Norwegian, Portuguese, Spanish, and Swedish.
Norms for the IDS-2 in every language were calculated using the state-of-the-art psychometric technique known as “continuous norming” and are supplied via the online Hogrefe Testsystem (HTS). Scoring for the IDS-2 is free of charge (pricing is included with the purchase of printed test protocols).
Continuous Norming allows for more precise calculations, and therefore are considered more appropriate for interpretation, particularly at the younger ages. The IDS-2 provides standardization data at one-month intervals, making printed booklets impossibly large. Therefore, Hogrefe created the innovative NormViewer technology to provide access to the calculated tables, if desired, with just a few clicks inside of HTS.
Learn more about the Continuous Norming process.
Learn more about the IDS-2 NormViewer technology.
The reliability of the IDS-2 was established by measuring internal consistency using Cronbach’s alpha in each language, along with additional test-retest studies (when appropriate).
With respect to validity, several studies in the UK, German, Dutch, and Italian languages were completed that showed very good correlations to other cognitive assessments (e.g., the WISC®-V, IDS and WISC-IV); the BRIEF®2 for executive functions; and the MABC-2 for psychomotor development). Other studies were conducted to measure criterion validity (e.g., with school performance) and differential validity (e.g., ADHD, autism spectrum disorder, intelligence impairment, exceptional talent).
As the studies vary by language and country, we have compiled a complete list of IDS-2 international validity tables.
Learn more about the IDS-2 international validity studies.
