ritics of the Texas textbook selection process won a significant victory last week when the state board of education voted to give proponents of particular textbooks an equal voice with opponents in deciding which books are chosen for the state's public schools.

Texas is one of about two dozen states that has a statewide selection system, and because it is one of the top five textbook purchasers in the nation, what passes muster in Texas often influences what is read by children in other states.

The Texas system came under attack last summer by People for the American Way, an organization founded by television producer Norman Lear to combat the influence of the New Right. Representatives of the group charged in a well-publicized presentation that the Texas system allowed only opponents of proposed texts to participate in the public hearings and thus opened up the possibility of censorship of texts without an adequate hearing.

People for the American Way and others who joined them were particularly upset about the influence of a Longview couple, Mel and Norma Gabler. The Gablers have been testifying against portions of textbooks under consideration in Texas for two decades, and their extensive textbook research is used by many conservative groups around the country.

The Gablers have defended their role, arguing they are doing only what the law allows, which is to register objections to particular texts or passages in books.

But the state board of education decided last week to expand the process by allowing people who want to argue for particular textbooks to participate.

Under the changes adopted, any citizen would have the right to file a bill of particulars supporting or opposing a book and then file written responses to the comments of others. In addition, anyone who has filed something in writing would be allowed to participate in public hearings held each August.

"We got every change we had requested," said Michael Hudson, Texas coordinator for People for the American Way. "Now you have a chance to say something positive about the books, and, more important, say something about the criticism of others."

Norma Gabler said Friday that the changes were not made to improve textbooks but to silence their own protests.

"Their aim has been to stop the Gablers," she said of People for the American Way.

The Texas legislature will hold hearings soon on legislation implementing the proposed changes. An aide to the Senate State Affairs Committee predicted the bill would be approved, despite anticipated opposition from New Right groups.