Today’s post was written by Riette Smit, an occupational therapist trained in ASI® , long term board member of SAISI and the 2017-2019 outgoing chairperson of SAISI.
As an occupational therapist I have often been faced with the question, “What makes our [occupational therapy] assessments different to assessments other therapists and teachers use?” Regarding sensory integration: What is the difference between tests such as the Sensory Processing Measure (SPM) and Sensory Integration and Praxis Tests (SIPT), and what distinguishes them from other tests measuring sensory integration function?
Some tests require training and a process of qualification for the therapist before she is a qualified test user. Other tests can be downloaded easily from the internet, without any prior training or learning attached to the test.
In any comparison of assessments it is important to establish whether the same parameters were measured, i.e. “to compare apples with apples.”
The value, usefulness and reliability of the interpretation of any assessment are greatly influenced by the statistical reliability of the collected data. This rests on four factors: standardization, reliability, validity and the adaption to the South African population.
Let’s have a look at the standardization of the Sensory Integration and Praxis Tests (SIPT) which is widely used by occupational therapists trained in Ayres Sensory Integration®. The SIPT represents a culmination of Dr. A Jean Ayres’s lifework. It is based on theoretical concepts and research that evolved over four decades. In the early 80’s extensive field and pilot tests were done in Southern California and Chicago. The SIPT’s primary purpose is to provide information on a child’s sensory integrative and praxis function. It provides an in-depth look at the child’s sensory systems functioning. The test contains 17 subtests and takes about 2 hours to complete. Therapists involved in the data collection process underwent training in the administration and scoring of the SIPT. The 1980 US Census was used to ensure appropriate representation of the US population in the normative sample. Variables considered were age, sex, ethnicity, and type of community. The final number of children tested (normative sample) was 1997 children. These children were selected from 9 geographic divisions.
Let’s have a look at the reliability of the SIPT. The reliability of a test indicates the extent to which the outcomes are consistent when the test is done more than once or in different testing situations. Test reliability also includes consideration of error related to lack of consistency in human performance and test imperfections. This means that trained SIPT therapists will get similar results when administering the SIPT.
Another important aspect we need to consider is the validity of a test. Validity is the extent to which a test measures what it claims to measure. It is very important for a test to be valid in order for the results to be accurately applied and interpret by the therapist. The SIPT has a very good validity within the subtests.
A very important consideration is how the test one is using, is adapted to the South African population. There are pertinent differences in some areas of development when we look at children globally. For example, South African children are found to have better developed motor skills than children in USA and Europe. To what extent are these factors accounted for in assessments? Research by Dr. Annamarie van Jaarsveld indicated which subtests within the SIPT needed to be adapted for the South African population.
In summary, when comparing assessments used by a variety of therapists and teachers, ask yourself the following questions:
a) Is this test standardized? On how many children was it standardized? Is that a good representation of children regarding age, sex, culture and demographics? Is training for the therapist required in administration and scoring of the test to interpret results successfully?
b) Is the test reliable? Will the outcome of the test be the same should it be done in different settings and by other trained therapists?
c) What is the validity of the test? Does it test what it says it will test?
These are questions any parent can ask to determine the efficiency of an assessment as well as the accuracy of test results.
- Mailloux, Z. (1990). An Overview of the Sensory Integration and Praxis Tests. American Journal of Occupational Therapy, 44, 589-594.
- Ayres, A.J. 2004. Sensory Integration and Praxis Test Manual, updated edition. Eighth printing. Western Psychological Services, Los Angeles
- Van Jaarsveld, A, Raubenheimer, J & Smith Roley, S. 2011. Patterns of Sensory Integration Dysfunctions in South African Children. In process of writing up.