Intelligence, aptitude and achievement tests on the NCE: Wechsler, Stanford-Binet and the theories behind them.
Names, ages and one distinction. Here is how the ability tests and the intelligence theories are sorted for the exam, and the single rule that separates aptitude from achievement.
By Dr. Andrew Wichterman · October 16, 2026 · 5 min read
AI-narrated overview made with Google NotebookLM. The written article below is by Dr. Andrew Wichterman.
Ability testing shows up on the NCE in two ways. A stem describes a test and asks you to name it, or a stem names a theorist and asks which theory he or she proposed. Both are recognition questions. You do not need to administer these instruments. You need to place each one quickly.
This post is the catalog: the history, the Wechsler scales, the other individual and group tests, the aptitude and achievement split, and the ethics of reporting a score. For the broader list of instruments, see assessment instruments you must recognize. Here we go deeper on ability.
The practice item in this article was written for this site in the style of the NCE. It is not a question from the actual exam. NBCC does not release its items, and candidates sign a nondisclosure agreement.
A short history of intelligence testing
Alfred Binet and Théodore Simon built the first practical intelligence test in Paris in 1905. The goal was modest: find children who needed help in school. Lewis Terman adapted their work in 1916 and called it the Stanford-Binet.
William Stern added the ratio IQ, which divides mental age by chronological age and multiplies by 100. That formula was later replaced by the deviation IQ, because variability differs from one age to the next.
- Binet and Simon, 1905: the first practical intelligence test.
- Terman, 1916: the Stanford-Binet.
- Stern: the ratio IQ, MA divided by CA times 100.
The theories of intelligence, one line each
Theory questions are matching questions in disguise. Learn the name and the claim together.
- Spearman: a general factor, g, plus specific factors. This is the two-factor theory.
- Thurstone: seven primary mental abilities.
- Cattell and Horn: fluid and crystallized intelligence.
- Gardner: multiple intelligences, eight of them, from linguistic to naturalistic.
- Sternberg: the triarchic theory of analytical, creative and practical intelligence.
- Goleman: popularized emotional intelligence.
Exam tip. When a stem lists analytical, creative and practical, the answer is Sternberg. When it lists a general factor and specific factors, the answer is Spearman.
The Wechsler scales and their age ranges
David Wechsler's scales are the most widely used individual intelligence tests, so the exam returns to them often. The three versions are split by age, and the age is the whole question.
- WPPSI: about ages 2½ to 7.
- WISC: ages 6 to 16.
- WAIS: ages 16 and up.
Current editions give a Full Scale IQ plus index scores for verbal comprehension, visual spatial, fluid reasoning, working memory and processing speed. The mean is 100 and the standard deviation is 15. Giving these tests takes graduate training, and the Wechsler scales are Level C instruments. The WIAT, the Wechsler Individual Achievement Test, is the companion measure of achievement.
Other individual and group tests
The Stanford-Binet is now in its fifth edition, the SB5, and covers ages 2 to 85. It reports fluid reasoning, knowledge, quantitative reasoning, visual-spatial processing and working memory.
- Kaufman Assessment Battery for Children: emphasizes processing and reduces cultural loading.
- Woodcock-Johnson: cognitive and achievement batteries for ages 2 to 90, and standard in learning disability evaluation.
- Raven's Progressive Matrices and the Cattell Culture Fair test: try to reduce language and cultural loading.
- Otis-Lennon School Ability Test and Cognitive Abilities Test: group-administered ability tests.
- Peabody Picture Vocabulary Test: screens receptive vocabulary.
One caution on the culture-fair tests. They reduce the influence of language and culture. They do not remove it. No test is culture-free, and an option that says otherwise is wrong.
Aptitude versus achievement
These two categories overlap in content, so the exam separates them by purpose. An aptitude test predicts future learning or performance. An achievement test measures what has already been learned.
- Aptitude: the SAT, the ACT, the GRE, the Differential Aptitude Tests and the ASVAB.
- Achievement: the Woodcock-Johnson achievement battery, the WIAT, the Wide Range Achievement Test, the Stanford and Iowa achievement batteries, and classroom tests.
Two more pairs belong here. Speed tests use many easy items under a strict time limit. Power tests use items of rising difficulty with generous time. And a learning disability is often defined by a gap between ability and achievement or, increasingly, by response to intervention.
How this shows up on the exam
Expect a description with the answer hidden in one detail. A stem that gives a client's age is pointing to a Wechsler version. A stem that says the test is meant to predict how a student will do in college is pointing to aptitude. A stem that says the test measures what a student has learned in reading and math is pointing to achievement.
The distractors sit right next to the answer. The WISC and the WAIS overlap at age 16, so read the age carefully. Aptitude and achievement tests can look similar on the page, so ask what the test is for, not what it contains.
A counselor is asked to select an instrument for a 5-year-old being evaluated before kindergarten. The counselor wants a Wechsler scale. Which is the best choice?
- WAIS
- WISC
- WPPSI
- Wide Range Achievement Test
Show the answer
C. The WPPSI covers about ages 2½ to 7. The WISC is tempting because it is the best-known child version, but it begins at age 6. The WAIS is for ages 16 and up, and the Wide Range Achievement Test is not a Wechsler scale.
Using ability tests ethically
Scores are not exact points. Interpret them with the standard error of measurement and confidence bands. Take language, culture, disability and testing conditions into account.
Do not report a single IQ number alone. Report it with the index scores and the context around it. A diagnosis of intellectual disability needs two things: an IQ about two standard deviations below the mean, and deficits in adaptive functioning, measured with an instrument such as the Vineland.
Results go only to qualified persons or with consent, and you explain them to the client in language the client can follow.
Check the current handbook. Exam logistics, fees and policies change. Confirm specifics against the NBCC candidate handbook and your state board's current rules. Aligned to the current NCE blueprint, valid for exams through June 30, 2027.
Match the age to the Wechsler, match the purpose to aptitude or achievement, and never report a bare IQ.