Assessing/Testing for Giftedness:
Dr. Silverman proactively lobbies for the continued use of the Stanford-Binet (Form L-M) Test to adequately assess highly and profoundly gifted children and has written many articles professing its strengths over current versions of SB for upper-range testing, including the following:
Why We Use the Stanford-Binet (Form L-M)
Linda Kreger Silverman
Gifted Development Center
The Stanford-Binet Intelligence Scale, Form L-M (SBL-M), is one of many IQ tests we use at the Gifted Development Center. We often administer two different intelligence scales to our clients. We give the SBL-M as a supplementary test to children who reached the ceiling (>99th%) on more recently-normed test, such as the Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV). While it is somewhat older, the SBL-M is clearly still a valid test, or it would not be listed as such in the current Riverside catalog. The 2002 Riverside catalog states:
Form L-M, with its lower floor and higher ceiling, is diagnostically appropriate for children at the extremes of mental ability. It can be used to evaluate levels of mental retardation and intellectual giftedness. (p. 24)
The Stanford-Binet was designed by Lewis Terman and his colleagues at Stanford University. It was called the "Stanford-Binet" because it was modeled after the children's intelligence test developed by Alfred Binet in France at the turn of the century. Terman also conducted the most famous longitudinal study of gifted individuals, described in his 5-volume, Genetic Studies of Genius. Participants in his study qualified on the basis of their performance on Terman's Stanford-Binet Scale. Therefore, Terman designed the scale with the specific intention of identifying extremely advanced children who might one day earn the label, "genius." No other individual intelligence scale was constructed with this intent, and none is able to capture the full strengths of the abilities of highly, exceptionally and profoundly gifted children. The Stanford-Binet Intelligence Scale, in all of its editions, remained the test of choice for identifying gifted children, by such notables as Nancy Bayley, Jerome Sattler and Ruth Martinson, until 1986.
Sadly, the fourth edition of the Stanford-Binet Scale, released in 1986, by the late Robert Thorndike, Elizabeth Hagen and Jerome Sattler, was not true to Terman's intent. It originally was planned to have a ceiling of 148, because, as all three authors told me, there weren't enough children in the norm sample who scored beyond 148 to warrant higher scores. Scores from 149 to 164 were statistically extrapolated by Robert Thorndike, rather than based on normed samples. Items for the test were designed for the general population, not the gifted population. In an interview that I conducted for a special issue of Roeper Review on the "IQ Controversy," Elizabeth Hagen made the following statement:
In the construction of the Binet [Revision IV], I was working with some nonverbal items that could only be solved by children who were in classes for the gifted. You can't put items like that in an intelligence test because they aren't functional for a wide enough group. (p. 171)
While most school psychologists are trained that "newer norms are better norms," it was clear to those of us who worked with gifted children that newer tests with newer norms could not differentiate children in the higher IQ ranges. For that reason, we have continued to use an older test that provides more accurate information about the true extent of the child's abilities, rather than use only the newer tests with lower ceilings that disguise the exceptionally gifted child as moderately gifted. We have seen dramatic differences in the thought processes, need for advanced work, social concerns, and emotional development of children beyond 160 IQ, compared with children who scored within the norms of current IQ tests. The additional information about the child's extraordinary abilities provided by the SBL-M is essential to the welfare of the child. It directly affects the particular recommendations that we make for a child. Without it, we would have considerable uncertainty about a child's needs.
The reasoning that newer norms are more reflective of the population is based primarily on observations of James Flynn. Flynn found that the general population is increasing in intelligence by approximately 1/3 of an IQ point per year across the globe. While that body of research was primarily done with nonverbal tests, such as the Raven's Progressive Matrices, an argument could be made that 1/3 of an IQ point should be subtracted from the child's score on the SBL-M for each year from the time the test was last normed in 1972. In other words, the SBL-M score of a child tested in 2002 might be diminished by 10 points. However, the antiquated wording and questions in the SBL-M penalize modern children by at least that many IQ points. In addition, the "Flynn effect" is not equally distributed across all IQ ranges. John Wasserman, then Director of Psychological Assessments at Riverside Publishing, and original project director of the fifth edition of the Stanford-Binet Intelligence Scale, wrote:
Although we standardly recommend that the most contemporary norms be utilized for any test, it has not been effectively demonstrated that phenomena such as the Flynn effect (the notion that norms become obsolete over time due to improvements in population intelligence) apply to changes in abilities at the extreme ranges (i.e., for individuals at very high or very low levels of ability). Indeed, there are sound statistical reasons for assuming that there may be only very minimal changes at the extremes of ability and that most of the changes in question occur for children and adults near the population mean. Moreover, Form L-M is one of the few reasonable options given the dearth of intelligence tests with sufficient ceiling to assess extremely gifted children. (J. D. Wasserman, personal communication, December 23, 1997)
Riverside Publishing is now conducting studies comparing performance on the SBL-M with performance on the Stanford-Binet Intelligence Scale, Fifth Edition. John Wasserman added in his letter, "Many of the changes we are planning for the Stanford-Binet Fifth Edition reflect ideas you have addressed in your research." Stanley E. Jones, Director of the Office of Ethics for the American Psychological Association, wrote:
It would not be my reading that Principle 2.9 would prohibit the use of any test for a purpose that can be defended. It does make it the responsibility of the psychologist to provide such a defense when using tests which are not obviously current. (personal communication to Sylvia Rimm, November 25, 1991)
John Wasserman continued, "We consider your continued use of Form L-M for gifted assessment to be reasonable and sound, based upon an informed knowledge of the literature." We believe it is defensible for examiners to use the SBL-M in order to differentiate children at the highest levels of intelligence. There is no current alternative.
In 1989, Kathi Kearney and I wrote an article in the refereed journal, Advanced Development, outlining the conditions under which the SBL-M should be given as a supplementary test. We were invited to write a more extensive article on this topic in 1992 for a second refereed journal, Roeper Review: "The Case for the Stanford-Binet L-M as a Supplemental Test." The practice of offering the SBL-M as a second test when children have hit the limits of the first test is common among those who work with the exceptionally gifted.
We will continue to administer the Stanford-Binet Intelligence Scale, Form L-M, at the Gifted Development Center, as a supplemental test for children who score at or near the ceilings of modern tests, and when requested. We will remain a training center where individuals can learn to administer and interpret this valuable clinical tool. Please see the free articles on our website: www.gifteddevelopment.com for more information about the current uses of the Stanford-Binet (Form L-M).
To date, there has been no pronouncement that use of the SB(L-M) will be discontinued, although Riverside Publishing has made no assurances about its continued availability.