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by Carol Evans

There are a number of journal articles, mostly in blindness related literature, which I will dig out and cite here if anyone is interested. What I can start here with is the questions one must ask about the particular child to be tested prior to selecting instruments.

General principles that apply to testing of any child apply here. The testing should be guided by the referral question, and must be administered in a way that does not penalize the child on the basis of the vision loss.

Sharon Bradley-Johnson, a SP (school psychology) professor at Central Michigan, has written books on the testing of BVI children (and also on the testing of D/HH children). They are available from PRO-ED, and are excellent references to start with.

It cannot be emphasized too strongly that the school psychologist should collaborate with the teacher of the visually impaired in designing the assessment and interpreting the results. The TVI will have detailed information on the child, the course of his/her individual loss of vision, and discussion and reading material on the specific effects of the child's particular eye disorder on vision. There are many, many different eye conditions, and they affect vision differently. Some result in loss of the central field, which affects reading and perception of fine detail. Others result in the loss of peripheral field, causing mobility problems, but leaving reading vision intact in the initial stages. Some eye conditions cause general loss across the whole visual field. Some children have vision that is variable from day to day, in different lighting conditions and weather. Some eye conditions vary with general health.

Some eye conditions are associated with syndromes that have other effects on learning and behavior.

Generally speaking, the visually impaired child, with no other significant disabilities, who has had early intervention, good quality teaching with the involvement of a qualified teacher of the visually impaired, materials provided in an appropriate format (whether large print, magnification, tactile, auditory, etc.) and who has the benefit of a supportive family, should achieve at levels comparable to those of sighted children with similar advantages.

That said, just as there is enormous variability among sighted children, there is also similar variability among the visually impaired. And just as has been said about other populations, blindness or visual impairment does not exclude the possibility of concomitant learning disabilities.

The Wechsler Verbal Scale has traditionally been considered to give results that are comparable with those for sighted children. There are, nevertheless, certain items which may present problems for some types of visually impaired children, particularly the totally congenitally blind. Easy questions involving concrete concepts learned primarily through vision may be failed, while more difficult questions involving abstractions may be passed. Eg. "What does transparent mean?"

The Wechsler verbal scales are generally considered adequate for students who are blind enough that they use braille. For students with low vision, particularly with enough vision that they use vision as a primary learning channel, the Verbal scales alone are, IMHO, inadequate.

Some of the subtests of the Performance scale, however, have timing procedures which discriminate against those with low vision. They allow for bonus points for rapid completion of certain tasks. Some do not give the performance subtests at all. If given, they should not, I mean never, I mean under NO CIRCUMSTANCES be computed into a Performance IQ, and then combined with the Verbal to yield a Full Scale IQ. There is value, however, in administering these subtests for the purpose of deriving qualitative information which can point to appropriate modifications of classroom materials and instructional methods.

Examples of such qualitative information might include the following:

  • "Jimmy was able to correctly complete some of the more difficult items on Block Design, but he required about 50% more time than is standard for fully sighted children of his age."
  • "Tony's performance on Picture Arrangement was affected by his visual loss in that many of the critical discriminating features of the pictures were too small, and of low contrast."
  • "Nancy's performance on some of the items of Object Assembly was slower than that of sighted children her age because of her spotty visual field loss (necessitating head turning and tilting in order to see the full array of pieces) as well as her slower fine motor responses, both of which are associated with mild cerebral palsy due to prematurity."

I find the Stanford-Binet: 4th Edition to be quite useful in assessment of children with low vision, because the only subtest (Pattern Analysis, which is analogous to Wechsler's Block Design) which has timing as an element has such generous time limits that every low vision child to whom I have administered it has been able to complete the designs within the time limits, if they are able to complete it at all. In fact, one or two have demonstrated that their visual abilities are superior to their verbal abilities, and that is important information to have.

There is the matter of making visual stimuli accessible. In a phone conversation over a year ago with Dr. Sharon Bradley-Johnson, she stated that any visual accommodation that helps the child in the classroom is appropriate for testing. Enlarged or magnified materials, etc. Does this violate standardized procedure? Yes, but so does giving the test to people not represented in the sample.

When stimuli are enlarged on a copier, color is lost. That is a problem if color is a factor in the test. A better solution may be to place the original stimuli under a video magnifier.

Every report I write on a visually impaired child contains some version or another of the following idea.

"These results should be interpreted with caution inasmuch as the instruments were standardized on a sighted population, and, certain accommodations were made for the student's access to the visual materials."

I'd like to add a word or two about achievement tests. Diagnosis of learning disabilities cannot be made on the basis of group tests such as the Stanford Achievement Test. It is necessary to administer an individual achievement test, such as the Woodcock-Johnson--Revised. For a low-vision student, I would suggest following the above recommendations about enlargement or use of video magnification. For braille students, the issues are different. About 5 years ago I brailled the relevant student portions for an eighth grade student. I followed the format of the print, with the same number of items per page. I did not have to do the very early items since he was an academically able blind student.

Last year I found that a braille version was available, and ordered it from the source listed in Louis. When it arrived the booklet included a caveat that it was brailled in accordance with the requirements of the agency which first requested it. I found it very inadequate, and had to modify procedures when administering it. It needs revision. So if you must, use it with caution. Examples of its inadequacy include: 1. the crowding of many items per page 2. the use of words to represent pictures which are used in questions involving quantity. An example would be the words fish fish fish on an item requiring the counting of the fish, and similar use of words to replace pictures on other arithmetic items. This will present a problem when using the test for kids with reading problems, as I did. A better way would be to use braille full cells. If the picture items in a question are different from one another, braille X's could be used. No, it does not directly reproduce the pictures, but neither do the words, and this way, the test will test what it is supposed to test (counting, addition, subtraction, etc.) and not reading.

Carol Evans