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 use the state-of-the-art psychometric technique known as “continuous norming” via the online Hogrefe Testsystem (HTS). Scoring is free of charge (pricing is included with the printed test protocol).
Continuous Norming allows for more precise calculations. The IDS-2 provides standardization data at one-month intervals, making printed booklets impossibly large. However, Hogrefe's innovative NormViewer technology in HTS provides access to the calculated tables with just a few clicks.
Learn more about the Continuous Norming process.
Learn more about the IDS-2 NormViewer technology.
Information on internal consistency and test-retest reliability is available in all languages. Studies are available on construct validity with various assessments (e.g. IDS, WIS-IV, M- ABC-2), on criterion validity (e.g., with school performance) and on differential validity (e.g., ADHD, autism spectrum disorder, intelligence impairment, exceptional talent) depending on the language.
Here you can find the complete list of IDS-2 international validity tables.
The reliability of the IDS-2 was established by measuring internal consistency using Cronbach’s alpha and with additional test-retest studies during the development of the UK edition.
With respect to validity, several studies in German, Dutch, and Italian were completed that showed very good correlations to other cognitive assessments (e.g., the WISC®-V) and was also found to be true in the UK. As the IDS-2 also measures other areas that provide a fuller picture of the individual’s strengths and areas for development, good correlations were also found with assessments designed to measure those constructs (e.g., the BRIEF®2 for Executive Functions; the MABC-2 for Psychomotor Development; etc.).
