John Pokrzywinski, MA West Tennessee Regional Office, Division of Mental Retardation Services & The Columbus Organization
For many years IQ tests and adaptive behavior scales have been the main instruments used to diagnose mental retardation and severity of impairment. IQ tests focus primarily on the optimal performance levels of tasks related to conceptual intelligence. Adaptive behavior scales focus on the skill level a person typically displays when performing tasks in the environment. Adaptive behavior scales usually measure aspects of conceptual, practical, and social skills. In addition to diagnosis, adaptive behavior scales are useful in identifying educational or training related goals. These goals are often based on identified deficits in specific skills (Schalock & Braddock, 1999; Widaman & McGrew, 1996).
The most widely used adaptive behavior assessments in the United States have included the Scales of Independent Behavior - Revised (SIB-R), the Vineland Adaptive Behavior Scales (Doll, 1935; Doll 1965; Sparrow, Balla, & Cicchetti, 1984); the AAMR Adaptive Behavior Scales (ABS) and the Inventory for Client and Agency Planning (ICAP) (Bruininks, Hill, Weatherman, & Woodcock, 1986; Johnson, 1989; Weatherman, Bruininks, Hill, & Woodcock, 1986). Each test measures skills that are related to, but distinct from academic ability and intelligence. Test results are generally be described qualitatively or as age-equivalents, percentile ranks, or standard scores.
The ICAP and the SIB-R Support Scores are equivalent. The scores were developed on the assumption that neither adaptive behavior nor problem behavior alone can predict the amount of care, supervision, or training an individual requires. The SIB-R and the ICAP have the same problem behavior scale. SIB-R/ICAP maladaptive behavior categories are mutually exclusive. The AAMR does not have a total score; data are averages for the two factors.
Luckasson et al. (2002) reviewed five measures of adaptive behavior. Of these, only the Vineland Adaptive Behavior Scales met the full requirements of the AAMR 2002 definition. The present commentary concerns the current advantages and disadvantages of using the Vineland in the diagnostic process and research with adults who have mental retardation.
The Supports Intensity Scale was developed over a period of five years by a team of 10 experts in assessment, psychology, and developmental disabilities (Thompson et al., 2003). The Scale builds on the work of the AAMR in the area of supports, especially the 10th edition of the association's classification manual titled Mental Retardation: Definition, Classification and Systems of Supports (2002).
The Supports Intensity Scale is divided into three sections, each of which measures a particular area of supports needs of the respondent:
"Section 1: Support Needs Scale of the SIS and consists of 49 life activities that are grouped into six subscales:
Health and Safety, and Social activities
"Section 2: Supplemental Protection and Advocacy Scale measures eight activities, but the score from this section is not used in the determination of the total Support Intensity Score.
"Section 3: Exceptional Medical and Behavioral Support Needs measures supports needs in 16 medical conditions and 13 problem behaviors commonly associated with intellectual disabilities.
When completing the SIS, the support needs for each life activity are examined with regard to three measures of support need:
"Frequency is concerned with how often "extraordinary support" (i.e., support beyond that which is typically needed by most individuals without disabilities) is required for each targeted activity.
"Daily Support Time assesses the amount of time that is typically devoted to support provision on those days when the support is provided.
"Type of Support reflects the nature of support that would be needed by a person to engage in the activity in question.
Supports Intensity Level is determined based on the Total Support Needs Index, which is a standard score, generated from scores on the subscales mentioned above.
There may be a tendency to confuse the Supports Intensity Scale with adaptive behavior scales since both are concerned with typical performance in everyday activities. Since the SIS and adaptive behavior scales measure are related, but different constructs, the scales should be used for different purposes. It is essential to understand that the SIS, as well as any other scale that is designed to measure support needs, does not supplant the need for adaptive behavior scales or other measures of personal competence that are essential for diagnosing the condition of intellectual disabilities. A key distinction between the two scales is that adaptive behavior stems are "skills" needed to successfully function in society, whereas the SIS items are activities attempt the identification of the type, frequency, and duration of supports required for the individual to complete those activities independently, or with minimal assistance.
To summarize, the SIS is a support needs assessment scale, and is not a scale to measure personal competence. Whereas intelligence tests and adaptive behavior scales attempt to directly measure aspects of personal competence, the SIS attempts to directly measure support needs. The reason for developing a support needs scale is that it is assumed that a direct measure of support needs will provide more specific and direct information and therefore will be more useful for planning teams and those involved in systems-level supports management who are trying to determine how to best support an individual in community settings.
Bruininks, R. H., Hill, B. K., Weatherman, R. F., & Woodcock, R. (1986). Inventory for client and agency. Itasca, Illinois: Riverside Publishing.
Doll, E. A. (1935). A genetic scale of social maturity. American Journal of Orthopsychiatry, 5, 180-188.
Doll, E. A. (1965). Vineland Social Maturity Scale. Circle Pines, MN: American Guidance Service.
Johnson, R. (1989). Review of the Inventory for Client and Agency Planning. In Conoley, J. C. & Kramer, J. J. (Eds.), Tenth Mental Measurements Yearbook (pp. 384-385). Lincoln: University of Nebraska Press.
Luckasson, R., Borthwick-Duffy, S., Buntinx, W. H. E., Coulter, D. L., Craig, E. M., Reeve, A., et al. M. E. (2002). Mental retardation: Definition, classification, and systems of supports (10th ed). Washington, DC: American Association on Mental Retardation.
Schalock, R. L., & Braddock, D. L. (1999). Adaptive behavior and its measurement: Implications for the field of mental retardation. Washington, DC: American Association on Mental Retardation.
Sparrow, S. S., Balla, D. A., & Cicchetti, D. V. (1984). Vineland Adaptive Behavior Scales. Circle Pines, MN: American Guidance Service.
Thompson, B. B., Campbell, E. M., Craig, E. M., Hughes, C., Rotholz, D. A., Schalock, R., et al. (2003). Supports Intensity Scale. Washington, DC: American Association on Mental Retardation.
Weatherman, R., Bruininks, R. H., Hill, B., & Woodcock, R. (1986). Inventory for client and agency planning. Rural Special Education Quarterly, 6, 58-59.
Widaman, K. F., & McGrew, K. S. (1996). The structure of adaptive behavior. In J. W. Jacobson & J. A. Mulick (Eds.), Manual of diagnosis and professional practice in mental retardation (pp. 97-110). Washington, DC: American Psychological Association.
Additional Suggested Reading
American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: Author.
Campbell, E. M., Fortune, J., & Heinlein, K. B. (1998). The effects of funding packages on the outcomes of integration and independence of adults with developmental disabilities in two rural states. Journal of Developmental and Physical Disabilities, 10, 257-281.
Campbell, E. M., & Heal, L. W. (1995). Prediction of cost, rates, and staffing by provider and client characteristics. American Journal on Mental Retardation, 100, 17-35.
Thompson, J. R., Hughes, C., Schalock, R. L., Silverman, W., Tassé, M. J., Bryant, B., et al. (2002) Integrating supports in assessment and planning. Mental Retardation 40, 390-405.
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