The Stanford-Binet Intelligence Scale

The Stanford-Binet Intelligence Scale is a standardised test that measures intelligence and cognitive abilities in children and adults, from age two through to mature adulthood.

Purpose

The Stanford-Binet Intelligence Scale was originally developed to help place children in appropriate educational settings. It can help determine the level of intellectual and cognitive functioning in preschoolers, children, adolescents and adults and assist in the diagnosis of a learning disability, developmental delay, mental retardation, or giftedness. It is used to provide educational planning and placement, neuropsychological assessment and research. The Stanford-Binet Intelligence Scale is generally administered in a school or clinical setting.

Precautions

The Stanford-Binet Intelligence Scale is considered to be one of the best and most widely used intelligence tests available. It is especially useful in providing intellectual assessment in young children, adolescents, and young adults. The test has been criticised for not being comparable for all age ranges. This is because different age ranges are administered different subtests. Additionally, for very young preschoolers, it is not uncommon to receive a score of zero due to test difficulty or the child's unwillingness to co-operate. Consequently, it is difficult to discriminate abilities in this age group among the lower scorers.

Administration and interpretation of results of the Stanford-Binet Intelligence Scale requires a competent examiner who is trained in psychology and individual intellectual assessment, preferably a psychologist.

Description

Administration of the Stanford-Binet Intelligence Scale typically takes between 45 to 90 minutes, but can take as long as 2 hours 30 minutes. The older the child and the more subtests administered, the longer the test generally takes to complete. The Stanford-Binet Intelligence Scale is comprised of four cognitive area scores which together determine the composite score and factor scores. These area scores include:

• Verbal Reasoning,
• Abstract/Visual Reasoning,
• Quantitative Reasoning, and
• Short-Term Memory.

Abstract and visual reasoning are analysed in Stanford-Binet intelligence tests

Score is considered to be the best estimate of "g" or "general reasoning ability" and is the sum of all of subtest scores. General reasoning ability or "g" is considered to represent a person's ability to solve novel problems. The composite score is a global estimate of a person's intellectual functioning.

The test consists of 15 subtests, which are grouped into the four area scores. Not all subtests are administered to each age group; but six subtests are administered to all age levels.

These subtests are:

• Vocabulary,
• Comprehension,
• Pattern Analysis,
• Quantitative,
• Bead Memory, and
• Memory for Sentences.

The number of tests administered and general test difficulty is adjusted based on the test taker's age and performance on the sub-test that measures word knowledge. The subtest measuring word knowledge is given to all test takers and is the first subtest administered.

The following is a review of the specific cognitive abilities that the four area scores measure.

• The Verbal Reasoning area score measures verbal knowledge and understanding obtained from the school and home learning environment and reflects the ability to apply verbal skills to new situations. Examples of subtests comprising this factor measure skills which include: word knowledge, social judgment and awareness, ability to isolate the inappropriate feature in visual material and social intelligence, and the ability to differentiate essential from non-essential detail.
• The Abstract/Visual Reasoning area score examines the ability to interpret and perform mathematic operations, the ability to visualize patterns, visual/motor skills, and problem-solving skills through the use of reasoning. An example of a subtest which determines the Abstract/Visual Reasoning score is a timed test that involves tasks such as completing a basic puzzle and replicating black and white cube designs.
• The Quantitative Reasoning area score measures: numerical reasoning, concentration, and knowledge and application of numerical concepts. The Quantitative Reasoning area is combined with the Abstract/Visual Reasoning area score to create an Abstract/Visual Reasoning Factor Score.

• The Short-Term Memory score measures concentration skills, short-term memory, and sequencing skills. Subtests comprising this area score measure visual short-term memory and auditory short term memory involving both sentences and number sequences. In one subtest that measures visual short-term memory, the participant is presented with pictures of a bead design, and asked to replicate it from memory.

Results

The numbers of correct responses on the given subtests are converted to a Standard Age Score or SAS score which is based on the chronological age of the test subject. This score is similar to an I.Q. score. Based on these norms, the Area Scores and Test Composite on the Stanford-Binet Intelligence Scale each have a mean or average score of 100 and a standard deviation of 16. For this test, as with most measures of intelligence, a score of 100 is in the normal or average range. The standard deviation indicates how above or below the norm a child's score is. For example, a score of 84 is one standard deviation below the norm score of 100. Based on the number of correct responses on a given subtest, an age-equivalent is available to help interpret the person's level of functioning.

Test scores provide an estimate of the level at which a child is functioning based on a combination of many different subtests or measures of skills. A trained psychologist is needed to evaluate and interpret the results, determine strengths and weaknesses, and make overall recommendations based on the findings and observed behavioural observations.