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In order to provide quality and meaningful assessment of individuals with visual impairment, it is critical that we present information concerning issues related to visual impairment in the context of theoretical constructs of tests and measurement. Understanding of this dual framework allows assessment of students with visual impairment in a manner that will lead to improvement in quality of instruction and facilitate identification of other issues that may be impacting the student's ability to learn.

Confusion Regarding Validity

The difficulty of assessing students with instruments that are not "valid" for students with visual impairments has been the focus of recent concerns. This concern appears to be based upon confusion regarding the definition of "validity" and "normative" samples. Guidelines given to assessment and VI staff at the local district must clarify the definitions of each of these terms in order for staff to make the best possible decision regarding selection of instruments.

Validity is a statistical concept that focuses upon the extent to which an instrument measures the skill that it purports to measure. This is a separate issue from the normative sample. Determining whether an instrument is "valid" is a judgment that must be made jointly between the assessment and VI staff. Such a decision can. only be made by looking at the extent to which this instrument is providing us with useful and accurate information regarding the student's ultimate performance.

Our experience has been that some instruments do provide us with this type of information regardless of the inclusion of children with visual impairments in the normative sample. These assessments can present an accurate and useful overview of the student's abilities in this areas. They must, however, be completed with careful adherence to recommended modifications in administration and interpretation that are sensitive to the unique needs of the student with visual impairment.

Continued training must occur with assessment personnel at the local level to assist them in identifying those instruments that do provide a good basis of information. In addition, we must provide VI staff with concise information about modifications in test procedures and interpretation that allow for quality assessments.

Problems With Over-Identification

There are specific handicapping conditions that seem likely to be over-identified within a population with visual impairments. Assessment personnel are not always familiar with some of the specific developmental issues that may be associated with visual impairment and may, in fact, identify a secondary-handicapping condition that does not exist as a separate condition. An example of this would be the presence of autism in a student with congenital visual problems. Another would be the presence of a learning disability in a student that is the result of a change in learning medium.

We must provide clear guidelines to assessment personnel regarding ways that secondary handicapping conditions can be differentiated from the issue of vision. TSBVI has begun efforts to develop specific procedures for differential diagnosis in these areas that we perceive as needs. We are committed to assisting in the appropriate diagnosis of secondary handicapping conditions in order to provide quality instruction that is sensitive to all needs of the student.

Problems With Under-Identification

Contact with local personnel suggests that many issues are often under-identified by assessment procedures. Admission to gifted and talented programs are often denied to students with visual impairment because of specified testing procedures. For example, many districts continue to rely upon measures of creativity that concentrate upon visual-spatial skills. Flexibility of assessment procedures for gifted and talented seem to be quite limited in a variety of districts in Texas. Information and observation indicate that students with visual impairments are likely to be under-represented in gifted and talented programs throughout the state.

The diagnosis of learning disabilities also is an area that has presented difficulties in UNDERIDENTIFICATION. TSBVI is again in the process of developing procedures and guidelines for accurately determining the presence of learning disabilities within a population of visual impaired students. Such guidelines will be available to local districts in order to assist them in identifying this population and in providing appropriate educational services within their local district.

Confusion Regarding Roles of the Assessment and VI Staff

The process of the Comprehensive Individual Assessment of a student with a visual impairment. It requires a collaborative approach that ensures that both the teacher of students with visual impairments and assessment staff confer about their respective areas of expertise with a mutual goal of quality assessment. The teacher of students with visual impairments must provide specific information about the individual child and modifications that must be made. In addition, they must be clear in specifying the unique impact that visual impairment has upon general patterns of development and learning. This professional exchange between teachers of the visually impaired and assessment staff is critical in ensuring that the assessment represents a valid estimate of overall strengths and needs of the individual child.


This document is a Resource for the Expanded Core Curriculum. Please visit the RECC.