Conspicuously missing from the debate over the No Child Left Behind (NCLB) Act is a discussion of how it has hurt many of our most capable children.

By forcing schools to focus their time and funding almost entirely on bringing low-achieving students up to proficiency, NCLB sacrifices the education of the gifted students who will become our future biomedical researchers, computer engineers and other scientific leaders.

The drafters of this legislation didn't have to be rocket scientists to foresee that it would harm high-performing students. The act's laudable goal was to bring every child up to "proficiency" in language arts and math, as measured by standardized tests, by 2014. But to reach this goal, the act imposes increasingly draconian penalties on schools that fail to make "adequate yearly progress" toward bringing low-scoring students up to proficiency.

While administrators and teachers can lose their jobs for failing to improve the test scores of low-performing students, they face no penalties for failing to meet the needs of high-scoring students.

Given the act's incentives, teachers must contend with constant pressure to focus their attention simply on bringing all students to proficiency on grade-level standards.

My district's elementary school report card vividly illustrates the overriding interest in mere proficiency. The highest "grade" a child can receive indicates only that he or she "meets/exceeds the standard." The unmistakable message to teachers — and to students — is that it makes no difference whether a child barely meets the proficiency standard or far exceeds it.

Not surprisingly, with the entire curriculum geared to ensuring that every last child reaches grade-level proficiency, there is precious little attention paid to the many children who master the standards early in the year and are ready to move on to more challenging work.

What are these children supposed to do while their teachers struggle to help the lowest-performing students?

Rather than acknowledging the need to provide a more advanced curriculum for high-ability children, some schools mask the problem by dishonestly grading students as below proficiency until the final report card, regardless of their actual performance.

Perhaps these schools, along with the drafters of NCLB, labor under the misconception that gifted students will fare well academically regardless of whether their special learning needs are met.

Ironically, included in the huge body of evidence disproving this notion are my state's standardized test scores — the very test scores at the heart of the No Child Left Behind Act. Reflecting the schools' inattention to high performers, they show that students achieving "advanced" math scores early in elementary school all too frequently regress to merely "proficient" scores by the end. In recent years, the percentage of California students scoring in the "advanced" math range has declined by as much as half between second and fifth grade.

Many gifted students, of course, continue to shine on standardized tests regardless of the level of instruction they receive. But whether these gifted students — who are capable of work far above their grade level — are being appropriately educated to develop their full potential is not shown by looking at test scores measuring only their grade-level mastery.

Nor do test scores indicate whether these students are being sufficiently challenged to maintain their academic interest, an issue of particular concern in high school.

Shockingly, studies establish that up to 20 percent of high school dropouts are gifted.

When high school faculty members face the prospect of losing their jobs if low achievers do not attain proficiency, what percentage of their resources will they devote to maintaining the academic interest of high-level students? How much money will administrators allocate to providing advanced courses? How many of the most experienced teachers will teach honors, rather than remedial, classes?

Surely we can find a way to help low-achieving children reach proficiency without neglecting the needs of our gifted learners. If we continue to ignore gifted children, the NCLB may end up producing an entire generation of merely proficient students — a generation that will end up working for the science leaders produced by other countries.

Susan Goodkin lives in Ventura, Calif., and is an advocate for the education of gifted children. She wrote this commentary for The Washington Post.