SON-R Overview SON-R Overview SON-R 2.5-7 SON-R 2.5-7 SON-R 5.5-17 SON-R 5.5-17 Computerprogram SON-test Computerprogram SON-test


The SON-R 2.5-7 and the SON-R 5.5-17 are the latest revisions,
for younger and older children respectively,
of the Snijders-Oomen Nonverbal Intelligence Test.

The SON-R tests are individual intelligence tests for general application which do not require the use of spoken or written language.
Therefore, the SON-R tests are especially suited for children with problems in the area of language and verbal communication. This concerns:
  • children with language- speech- and hearing difficulties,
  • deaf children,
  • autistic children,
  • children with developmental delay and learning difficulties,
  • immigrant children raised with a different language,
  • and mentally retarded children and adults.

SON-R 2.5-7 "Analogies"

The SON-R tests consist of subtests related to:
  • abstract and concrete reasoning,
  • spatial insight
  • and visual perception.

Other characteristics of the tests are:

  • the feedback that is given after each item
  • and the adaptive test procedure.

In the table below, some information is given regarding both SON-R tests and the standardized shortened version of the SON-R 5.5-17.

Comparison SON tests

  SON-R 2.5-7 SON-R 5.5-17
Complete test Complete test Short form
Age range 2;6 - 6;11 5;6 - 16;11 5;6 - 16;11
Number of subtests 6 7 4
Duration 50' 90' 45'
Size of sample N=1124 N=1350 N=1350
Reliability .90 .93 .90
Generalizability .78 .85 .77
The correlation between the SON-R 2.5-7 and the SON-R 5.5-17, after an interval of three to four months, is .76.

Both tests have been standardized in the age range from 5;6 to 8;0 years.

With children of about 5 years old it would in general be better to use the SON-R 2.5-7.
At 6 years both tests are well suited, whereas for 7 year olds the use of the SON-R 5.5-17 is recommended, unless one suspects that the child lacks sufficient cognitive abilities.

SON-R 2.5-7 "Mosaics"

SON-R 5.5-17 "Mosaics"

The tests have been reviewed by the COTAN, the test commission of the Netherlands Institute of Psychologists.
The categories used are insufficient, sufficient and good.
The ratings are as follows:

   SON-R 2.5-7 SON-R 5.5-17
Complete test Complete test Short form
 Basics of the construction of the test  good  good  good
 Quality of the test materials  good  good  good
 Quality of the manual  good  good  good
 Norms  good  good  good
 Reliability  good  good  good
 Construct validity  good  good  good
 Criterion validity  good  good  good
The ratings of the tests are exceptionally high.

(Source: Evers, van Vliet-Mulder & Groot, 2000. Documentatie van tests en testresearch in Nederland. Assen: Van Gorcum / NIP. The SON-R 5.5-17 Short Version was reviewed by the COTAN in 2003.)


If you have any questions relating to the contents, procedures and psychometric aspects of the SON-R tests, which are not answered in these pages, please contact one of the authors:
Dr. P.J. Tellegen
or Dr. J.A. Laros.

The SON-tests are internationally published and produced by Hogrefe Verlag at Göttingen, Germany.

If you would like to learn about prices, or order the SON-R tests, please contact one of the publishers/distributors listed below:

The Test Agency
U.K. and English speaking countries

Hogrefe Verlag Testzentrale


Czech & Slovak Republic

Hogrefe Uitgevers
The Netherlands and Belgium

Hogrefe France

The tests are sold to qualified professionals only.

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