While psychological testing is aimed at assessing a wide spectrum of clients, special groups require special attention and hence need special instruments. In light of this, there a number of tools that have been developed in order to assess special groups. The following are two main instruments among those that have been developed to assess special groups:
Columbia Mental Maturity Scale – Third Edition (CMMS) – This is an alternative test that is designed to assess special population including those with mental incapacitation. This scale is aimed at addressing sensory and physical limitations that limits the administration of Binet, Wechsler, and other scales (Capuzzi & Stauffer, 2005). This scale is therefore suitable for children who experience physical limitations like cerebral palsy, speech impairment, loss of hearing and others. The scale requires no verbal response or fine motor skills and it measures general reasoning ability. One of the strengths of this test is that it has high internal consistency and high reliability. Major weakness is that the test is complicated and requires highly qualified personnel. Another major weakness is that it is highly vulnerable to random error.
Leiter International Performance Scale – Revised (LIPS-R) – Unlike the Columbia and other tests like Peabody that measures verbal intelligence, LIPS-R measures performance (Capuzzi & Stauffer, 2005). It provides non-verbal alternative to Stanford-Binet scale for individuals between the age of 2 and 18. One of the major strength of this test is that it emphasize on fluid intelligence which is a truest measure of person’s innate ability. It is not influenced by education background, social, and family experience. One of the major weaknesses of this test is that it is difficult to administer and requires highly qualified personnel.
I believe the above two scales would be most useful when dealing with special population because they cover limitations that inhibits on administration of other scales on the special population (APA, 2010). Due to limitations in different cognitive and physical areas, special population requires tests and assessments that cater for these limitations and the above tests have such provisions. Therefore, they are most suitable for testing and assessing that population.
For counselors, it is important to be aware of issues that are involved in testing special populations. Special populations like cerebral palsy children have cognitive and physical limitations from a normal population that should be catered for in counseling. Therefore, as a counselor or psychologist working in a diverse population, it is important to be aware of issues that re involved in testing special populations.