226 ❯ SteP 4. Review the Knowledge You Need to Score High
Validity—test measures what it is supposed to measure; methods of measurement
include face, content, predictive, construct.Types of tests:Performance tests—test taker knows how to respond to questions and tries to succeed.Speed tests—large number of relatively easy items in limited test period.Power tests—items of varying difficulty with adequate test period.Aptitude tests—assess person’s capacity to learn, predict future performance
(example: SAT).Achievement tests—assess what a person has already learned (example: AP test).Group tests—test many people at one time; test taker works alone; cheaper; more
objective.Individualized tests—interaction of one examiner with one test taker; expensive;
subjective grading.Ethics and standards in testing:APA and other guidelines detail standards to promote best interests of client, guard
against misuse, respect client’s right to know results, and safeguard dignity.Culture-relevant tests—test skills and knowledge related to cultural experiences of the
test takers.Intelligence and intelligence testing:Reification—construct treated as a concrete, tangible object.Intelligence—aggregate or global capacity to act purposefully, to think rationally, and
to deal effectively with the environment.Stanford-Binet intelligence test—constructed by Lewis Terman—was an individual
IQ test with IQ calculated using ratio formula: Mental age/chronological age × 100.
Now, IQ based on deviation from mean, for children and for adults. Five ability areas
assessed both verbally and nonverbally.Wechsler intelligence tests—Three age-based individual IQ tests: WPPSI (Wechsler
Preschool and Primary Scale of Intelligence), WISC (Wechsler Intelligence Scale
for Children), WAIS (Wechsler Adult Intelligence Scale); two scores—verbal and
performance; difference between the two is helpful for identifying learning disabilities;
deviation IQ score—100 mean/mode/median, 15 pt SD; good for extremes of gifted
and intellectually disabled.Degrees of intellectual disability range from mild to severe for individuals who score
at or below 70 on an IQ test such as the Wechsler:- Mild—(about 85 percent) can self-care, hold job, live independently, form social rela-
tionships. - Moderate—(about 10 percent) may self-care, hold menial job, function in group home.
- Severe—(about 3–4 percent) limited language and limited self-care, lack social
skills, require care. - Profound—(about 1–2 percent) require complete custodial care.