Typically, present levels of academic achievement are ascertained through a combination of curriculum-based assessment (CBA) and norm referenced achievement tests. Curriculum based assessment (CBA) determines how the child is progressing in and responding to the curriculum. Standardized norm referenced achievement tests are used to determine how to the child is functioning academically in relation to his or her cognitive capabilities.
Different achievement tests measure different constructs. For example, for a child who is suspected of having a specific reading disability, such as dyslexia, academic testing must include nonsense word reading in addition to real word identification. Dyslexic children have difficulty phonetically decoding words that are not in their sight vocabulary. It is only by using pseudowords, or phonetically regular nonsense words, that the psychologist can establish the child's phonetic decoding capabilities.
Many academic achievement tests are untimed. As a result, disabled children who do relatively well on achievement tests when given unlimited testing time may not appear to have any difficulties. In these cases, process assessment is imperative because it provides important qualitative data about how the child actually performed when taking the test.
If given unlimited testing time, dyslexic children can often "logic out" real words and comprehend the meanings of words and sentences. However, on a timed reading tests like the Nelson-Denny Reading Test or the Reading Fluency subtest of the Woodcock-Johnson Psychoeducational Battery-III, many dyslexic children experience extreme difficulty because they do not have extra time to compensate for their learning problems.
Many children with Non-Verbal Learning Disorders have difficulty with complex comprehension that involves inferential thinking, the prediction of cause-and-effect, and the ability to generate inferences. However, reading comprehension subtests such as those found on the Woodcock-Johnson Psycho-Educational Battery-III, do not tap into these higher-level comprehension skills.
In fact, children with NLD who have profound comprehension problems may do relatively well on the Woodcock-Johnson Reading Comprehension subtests, which reward the child with strong knowledge of the meanings of vocabulary terms. On the other hand, the Reading Comprehension subtest from the Wechsler Individual Achievement Test-Second Edition is imbedded with many items that require the child to predict cause-and-effect, generate inferences, separate relevant from irrelevant detail and engage in higher-level comprehension.
Children suspected of having a Non-Verbal or Right Hemispheric Learning Disorder would obtain a more accurate assessment of their academic achievement functioning on the Wechsler Individual Achievement Test-Second Edition.
Reliability and Validity of Test Measures
The results obtained in a psychoeducational evaluation are only as good as the tests administered. There are strengths and weaknesses associated with all tests on the market. Two concepts that the psychologist must consider when picking and choosing tests are the reliability and validity of test measures.
Reliability refers to the ability of the test to measure the same constructs consistently over time. If a test is unreliable, wildly disparate results may be obtained during test-retest situations. Validity refers to the ability of the test to accurately measure what it purports to measure.
Norm-referenced academic achievement tests provide important objective data about the child's present levels of academic functioning. This data can not only be used to determine the child's response to prior special education intervention but can serve as a baseline to measure the effectiveness of future special education initiatives.
When the psychologist assesses a child who is suspected of having specific learning disabilities, the child should be assessed in the areas of basic reading skill, reading comprehension, math reasoning, math calculation, spelling, written expression, listening comprehension and speaking.
Tests of Attention and Executive Function
Testing of attention and executive functions is rather complex because there is no single test that effectively ascertains functioning in these domains. Therefore, the psychologist must create a battery of tests and checklists, which provide both anecdotal information and objective evidence of the child's ability to attend, concentrate, control impulsivity and engage higher-level executive functions.
Attention Deficit Hyperactivity Disorder (ADHD) is the most common childhood neurobehavioral disorder and is found in 4 to 12 percent of all school-age children. When evaluating a child for Attention Deficit Hyperactivity Disorder, the psychologist must obtain direct information from the parents, classroom teachers, and the student's caregivers regarding the core symptoms of ADHD in various settings. This information includes the age of onset of symptoms, duration of symptoms and the degree of functional impairment that results from the symptoms.
Teacher narrative should also be included for information regarding the child's classroom behavior, learning patterns, classroom interventions which have been tried, degree of functional impairment, evidence of impact of ADHD on the child's school work, report cards and samples of school work.
The psychoeducational evaluation of a child suspected of having ADHD should also include assessment for co-existing conditions including learning and language problems, aggression, disruptive behavior, depression or anxiety. Psychologists should rely on guidelines from the DSM-IV to diagnose attention deficits in school-age children.