In the 1990s, Hooked on Phonics rode a backlash against so-called whole language reading instruction in schools to become an infomercial phenomenon.
But education experts and, at times, federal regulators have been skeptical of the company's claims that it could rapidly improve the skills of struggling young readers.
Education experts caution that it works only as an after-school adjunct to comprehensive reading instruction that teaches children more than sounding out letters and words.
"Phonics is critical in learning to read, but it's not sufficient. In looking at any reading program, it behooves the consumer to make sure it's comprehensive," said G. Reid Lyon, who is President Bush's reading adviser and heads a child development and behavior branch of the National Institutes of Health.
One measure of Hooked on Phonics' supplementary role is the scant academic research devoted to it, experts said.
Generally, public schools throughout Maryland don't use it much, said Bill Reinhard, a spokesman for the state Department of Education. Baltimore-area school officials said they don't use it systemwide, although individual teachers may.
When the Baltimore County school system supplemented its reading program last year, it looked elsewhere because the federal government hadn't approved Hooked on Phonics, said Jane E. Lichter, coordinator of elementary reading and language arts.
Experts say commercial reading programs like Hooked on Phonics tend to bolster some but not all of the skills that lead children to become successful readers.
They say research shows that children must be taught to sound out words quickly and accurately, expand their vocabularies and comprehend what they're reading.
"The question is not whether to use it or not, but to make sure the kids learn how what they have learned is applied to real reading," said Dorothy Strick- land, a professor at Rutgers University who specializes in reading.
Under the "whole language" philosophy, children build their reading skills and learn the meaning of words primarily through reading, de-emphasizing the sounds that letters stand for.
In 1994, Hooked on Phonics agreed to settle federal regulatory charges that it made unsubstantiated claims about the ability of its products to teach reading to children with learning disabilities.
Company officials say Hooked on Phonics wasn't designed to compete with schools' reading curricula. They say it's aimed at parents who want to help their children after school.
Several years ago, the National Institutes of Health studied Hooked on Phonics and found that it - like many commercial programs - didn't teach all reading skills, Lyon said.
Because of such issues, company officials say they overhauled Hooked on Phonics in 1997 and further revised it in 2000. On top of phonics lessons, it also teaches children how to read words quickly and accurately.
"That formula generates success for kids early on and gives kids confidence to keep reading," said Wendy Paige Bronfin, vice president of product development and education.
Robert E. Slavin, director of the Center for Data-Driven Reform in Education at the Johns Hopkins University, said: "If nothing else, it's provided a useful escape valve, if you will, for parents to take the situation into their own hands and try to help their kids improve their reading skills."
Sun staff writer Jamie Smith Hopkins contributed to this article.