You are spot on. A combination of cognitive/developmental level, and adaptive functioning is the standard in both research and clinical practice. You might need to do some cultural modifications.

In Norway, for cognitive testing, we use the Wechler Preschool and Primary Scale of Intelligence (WPPSI-IV), Wechler Intelligence scale for children (WISC-V) and Wechler Adult Intelligence Scale (WAIS-IV). WPPSI for children 3-7 years, WISC for children 6-16 years and WAIS for adults 16- 89 år. In Norway we also use the Leiter International Performance Scale (LIPS) og Wechler Abbreviated Test of Intelligence (WASI), but these have not been normed for Norwegian situation as the former three have. We use this in combination with the Vineland Adaptive Behavior Scales-Second Edition (Vineland-II) or Adaptive Behavior Assessment System- Second Edition (ABAS-II) because they are normed for Norwegian and Scandinavian situation. These tests are done in addition to intervju and observation and must be done by a specialist in Norway to be accepted. These are the requirements of The Norwegian Directorate of Health. Unfortunately the link is in Norwegian: https://www.helsedirektoratet.no/rapporter/utredning-og-diagnostisering-av-utviklingshemming/Rapport%20om%20utredning%20og%20diagnostisering%20av%20psykisk%20utviklingshemming.pdf/_/attachment/inline/f6c8ed73-c1d0-4819-9f83-b69bfbe17f38:bd58feb11efd678f91da43e173453bcef93ffb97/Rapport%20om%20utredning%20og%20diagnostisering%20av%20psykisk%20utviklingshemming.pdf

Dear Kjartan Skogly Kversøy , Thanks a lot for the insight in Norwegian practice.

Dear Rhianon Allen , Thanks for your reply. What kind of instruments would you recommend? I would be very interested in this fact.

My recommendation for cognitive/developmental assessment would depend on the age & expected functioning level Therefore, one of the disadvantages of the Wechsler series in assessing severe or profound disability is that each of the tests individually is too restricted in the range of cognitive ability they assess. For the Wechsler series, severe or profound disability is actually just a failure of the person to perform at the test minimum. Who wants to put a test taker through such a failure experience?

I would check to see if there is a German edition of the Stanford-Binet, which can test cognitive abilities beginning at the typical 2 year level. The Leiter is an acceptable alternative for non-verbal test takers, or if a German edition of the Stanford-Binet is not available; but for a test taker with verbal skills, it won't give you an estimate of verbal ability. The Woodcock-Johnson (published by Riverside) also has a wide developmental range but might not appeal to someone with profound disabilities because it doesn't have much manipulable material; also, I'm pretty sure that there is no German edition. I have even used the Bayley Scales many times for teenagers with profound disabilities, but the Bayley won't give a quotient for test takers older than 4 years. (Just a list of skills that the person can or cannot perform.) So: if the expected developmental level is that of an average two-year-old, see if you can find a German copy of the Binet. Failing that, go for the Leiter.

I very much like the Vineland for assessing adaptive behaviour over a very wide age and ability range. However, unless German norms are available, you will need to interpret the Vineland scores in light of what skills might not be part of a person's repertoire simply because German child rearing (or the person's caretakers) commonly doesn't expect them. The Adaptive Behavior Scale is a good alternative.

See Kjartan's note. I think that he is saying that the Vineland & ABS are normed for a Scandanavian sample. That could be a better cultural match than with the US norms.

Note that all the developmental tests are quite expensive, and that you need to establish your qualifications before the publishers will sell you a copy. So think hard about which test you want before you plunk down the money & go through the effort of qualifying for purchase.

Thanks a lot for this detailed explanation. While reading your abstract, I am not sure if we are talking about the same target group. I would agree with Nakken & Vlaskamp (2007) who defined that this target group “consists of individuals with such profound intellectual disabilities that no existing standardized tests are applicable for a valid estimation of their level of intellectual capacity” (i.e. developmental age up to 24) and additional motor impairments hinder this conduct, too. This fact would exclude most of the instruments you were talking about (also because of floor effects), wouldn’t it?

Even if these tests were appropriate, there would still be the problem that you already addressed: the training qualifications & the price.

In conclusion, I would not have expected direct testing but rather an interview with/a questionnaire for reference persons/proxies or a (standardized) observation. The reason is that almost all papers also state that they did not include direct testing without reporting the exact way of assessing and meeting the sample criteria.

So, the point is that that the core of my research is not about the cognitive level of people with PIMD. I just need to ensure and comply the sample criteria in a good and feasible way for the participants, their reference persons and me.

If your focus is on adaptive functioning and you do not need to assess cognitive functioning, then the Vineland or the Adaptive Behavior Assessment System are the way to go. They are completed by someone familiar with the target person. German editions might also be available, or it is possible to develop your own German version once you purchase the English edition. Both are relatively affordable, assess adaptive functioning that is probably in the range that interests you, and do not have the advanced qualification level to purchase.

I'm working on rehabilitative programs to promote adaptive behaviors in individuals with severe to profound developmental disabilities and multiple disabilities. I usually use the VABS to assess the severity of the disability and found it valid and reliable. Accordingly, I feel that the VABS constitutes a solid way to evaluate multiple disabilities. I wonder whether a german version is actually available in the literature.

Thanks a lot for your replies.

Would you also recommend the ABAS-II or III?

The reason for my question is that a project is currently working on a German translation.

Si vas a evaluar discapacidad intelectual severa creo que una escala de desarrollo (ej. BATTELLE) puede funcionar, también de aplica a personas con discapacidad motriz, visual y auditiva.