Helping older elementary school children who are struggling to read is even harder than some of the experts think.

A study involving 50 schools in the Allegheny County suburbs -- the largest of its kind in the nation -- showed that the intensive help provided for such students improved skills for third-graders but was less effective for fifth-graders.

And even where there was improvement in both grade levels, the help wasn't enough to catch up with the strong readers, who were continuing to advance.

"I don't think there's going to be any secret formula and no one thing that works for every child," said Joseph K. Torgesen, principal investigator of the Florida Center for Reading Research at Florida State University.

While they didn't catch up, the third-graders, in particular were "better off in terms of the lower-level word skills for having participated," said David Myers, senior vice president of Mathematica Policy Research.

The $9.6 million study was part of the Power4Kids Reading Initiative started by the Haan Foundation for Children of San Francisco and done in cooperation with the Allegheny Intermediate Unit.

The results were released this week. A total of 772 children with reading difficulties participated in the study during the 2003-04 school year.

More than 300 of the students were randomly assigned to a control group and received the regular reading instruction provided in their schools, which in some cases was quite a bit of extra instruction, Dr. Torgesen said.

The others received an average of 80 hours of help in small groups -- one teacher to three students -- using one of four reading programs: Spell Read Phonological Auditory Training (PAT), Corrective Reading, Wilson Reading or Failure Free Reading.

Dr. Torgesen said the programs concentrated on fundamental reading skills.

In some cases, the control group fell farther behind while the group receiving the extra help did not.

Dr. Torgesen said the older readers, in particular, may have benefitted more if they had had more instruction on comprehension skills.

From the results, Dr. Torgesen has this advice for parents: "If their child is at the low end, is a really struggling reader, somebody who is still in the third grade, still reads like a first-grader, they really should receive an intervention very much like what we provide to these children."

But for children who are a year or a year-and-a-half behind, he said, "They would be seeking out interventions that really focus powerfully on teaching kids directly how to comprehend what they read."

When she heard that third-graders fared better than fifth-graders, Robin Pleta, a resource support teacher at Eisenhower Elementary School in Upper St. Clair who participated in the study, likened it to learning a golf swing.

"If you can catch it and correct it early, it's a little bit easier to correct it. By the time you get to fifth grade, you've had five years of practicing skills that haven't served you well," she said.

Dr. Torgesen said he was both surprised and disappointed to discover that the interventions didn't work as well for low-income children.

"This amount of instruction doesn't appear to be enough or the right thing for many of the kids who need it the most," he said.