My Memorial Day dinner conversation was dominated for a while by an article in that day's Washington Post about Highland Elementary School in Wheaton pretty much jettisoning social studies and science instruction for many students in favor of intensive reading instruction.

Horrified, my mother-in-law -- a retired New York City elementary school teacher -- asked, "Can't they combine them?"

She is, of course, correct. Not only can schools combine reading with social studies and science, they must do so. Otherwise, they don't get readers; they get decoders who cannot understand what they are reading.

Schools and school systems that cut back on social studies and science in favor of reading instruction have misinterpreted what reading is and what federal education officials are calling for when they demand that reading instruction be scientifically based.

One of those officials is Chris Doherty, who heads the U.S. Department of Education's Reading First program, which provides extra money to needy schools to improve reading instruction. Doherty told me: "We never said throw out social studies and science. It never occurred to us that anyone would do that."

To sort through this issue, I sent an e-mail to G. Reid Lyon, who brought the term "scientifically based reading instruction" into the nation's schools. He is chief of the child development and behavior branch of the National Institute of Child Health and Human Development and an adviser to President Bush. His work is central to both the federal No Child Left Behind law and Reading First.

"What is surprising to me is that people continue to form false dichotomies between reading and content learning," he wrote back.

For much of his professional life, Lyon has had to battle the idea that students could learn social studies and science using audiovisual and other materials without ever reading. Now the opposite danger is threatening to emerge: Some educators might think it is possible to focus on reading skills without needing to teach the subjects that provide the background knowledge and vocabulary needed in reading.

"In order to understand what you are reading," Lyon wrote me, "you have to know what the words mean and also have background knowledge, or what some folks call 'world knowledge.' "

Lyon suggested I call Louisa C. Moats and E.D. Hirsch Jr. Moats has researched reading instruction and co-wrote a book I highly recommend, "Straight Talk About Reading: How Parents Can Make a Difference During the Early Years." Hirsch is a professor emeritus of education at the University of Virginia and is best known as the author of "Cultural Literacy."

"The problem in Maryland," Moats said, "is that the prevailing view of reading instruction did not include skillful teaching of reading." What is happening at schools such as Highland, she said, "sounds like an overcorrection."

"It's very important to use research-based instruction to teach kids to read," Moats said. "But it's not true that good reading instruction has to replace a curriculum that will build a knowledge base and vocabulary." As she said, "The curriculum is the reason kids learn."

For Moats, "an ideal combination would be a Core Knowledge curriculum, with all that entails in social studies and science," coupled with careful, research-based reading instruction.

By "Core Knowledge," Moats means a program that Hirsch developed that builds a broad knowledge of science, history, literature and art from kindergarten onward.

By research-based, or scientifically based, reading instruction, Moats means instruction that has been tested to make sure it helps students learn to read.

My description makes it sound pretty tame, but it is controversial. Reading instruction has been dominated for decades by fads and fashions that have left huge numbers of children and adults without the ability to read anything more complicated than a simple story. Many teachers and principals -- and, more important, education professors who teach teachers and principals -- resist mightily that they are obligated to demonstrate through rigorous research that the way they teach helps kids learn.

For a more complete explanation of what scientifically based reading instruction means, readers might want to look at a new book, "The Voice of Evidence in Reading Research," by Peggy McCardle and Vinita Chhabra. The book is most useful for teachers and principals bombarded with claims that a particular reading program is scientifically based, but parents could also find it helpful as an introduction to issues involved in reading instruction.

As for Hirsch, he considers what is happening at Highland an absolutely central issue. He is alarmed by the amount of time schools are putting aside for reading instruction, including in Montgomery County where schools spend from 90 minutes to two hours a day on reading.

"They all think the time spent on early reading will get kids to read," he said. "The experts say you only need 30 minutes a day on the technical aspects of reading, depending on the grade level. That's all you should do. What are you going to do with the rest of the time?"

He says that "substantive material has to be integrated into the reading program."

"None of the early reading programs enable the teacher to do this," he said.

Hirsch has been warning about the possibility of schools using test preparation as an excuse to drop content for a while. In a recent essay published by the Hoover Institution, where he is a distinguished visiting fellow, Hirsch wrote: "The dull exercises in 'comprehension strategies,' which have been shown to be largely useless, take up great stretches of time in all the reading programs. Hence the small initial rise in reading scores yielded by these intense, misguided efforts will level off to everyone's disappointment."

He is exactly right in the case of Highland. Last week, I wrote about the broad improvement in second-grade reading scores in Montgomery County schools. Highland was not one of the schools that improved. In fact, it was one of only 15 schools where the reading scores dropped this year. Of 19 schools in the county with similar demographics -- 71 percent of the students meet the income requirements for free and reduced-price meals, 66 percent of the students are Hispanic and 19 percent of them are African American -- Highland is at the bottom in academic achievement.

Because Highland is struggling, it is scheduled to become a Reading First school next year. That means during the summer and fall, its teachers are to receive training in what constitutes good reading instruction and what is required and not required by the federal program. Doherty said that because students are supposed to have a 90-minute block devoted to reading "doesn't mean kids are supposed to be sitting in their seats getting phonics instruction. These are little kids."

Montgomery Superintendent Jerry D. Weast says the situation at Highland should not be considered typical of what is happening in county elementary schools. "Highland is an anomaly. The others are teaching science. They are teaching social studies. They are integrating [students] into reading."

Weast acknowledges that schools are under pressure to cram a lot into a short amount of time, but he denies that they need to eliminate content in favor of reading. "If you look at the subjects as being discrete and not integrated, there will never be enough time in the day to teach everything," Weast said.

But "you can read about science, you can read about history," he said. "They bring reading alive and make it fun."

If he is right that the other schools are incorporating a coherent science and history curriculum into their reading instruction, then we should be able to see broad improvements in third-, fourth- and fifth-grade reading scores this month when the state's Maryland School Assessment test results are released. This is because the older kids become, the more their reading scores depend on background knowledge and vocabulary.

Second-grade reading scores reflect an ability to decode. The fact that more Montgomery County second-graders are improving at decoding is a big deal and worth noticing.

But the real test is yet to come.

Homeroom is a forum for you that appears every week in Montgomery Extra. Send questions, opinions and issues that you would like discussed to Homeroom, The Washington Post, 51 Monroe St., Suite 500, Rockville, Md. 20850. The fax number is 301-279-5665. Or e-mail homeroom@washpost.com. To see previous columns, go to www.washingtonpost.com/wp-dyn/education/columns/homeroom.