When best-seller book lists appear each week, most of us probably have little idea what they really mean. How many books were sold? Who bought them?

Yet the ranking of books suggests these are the most popular in the country.

Are they?

Some publishers have made an educated guess that sales of 300,000-400,000 copies are necessary for a book to make the best-seller lists. But it's just a guess.

The New York Times rankings are billed as a reflection of "sales figures at almost 4,000 bookstores plus wholesalers serving 50,000 other retailers." According to Stephanie Cerrito, a spokeswoman for the best-seller list at the New York Times, these figures are compiled from reports of sales from bookstores, then statistically weighted to represent sales in all such outlets nationwide. That means a book could make the list with lower sales figures one week than the next, and those figures, said Cerrito, "are a closely guarded secret."

John Wright, administrator of the New York Times list, said, "Book sales fluctuate so much from week to week that you can't give a concrete example. One week a few thousand may be enough to hit the top, and other weeks it is much more. So we give no figures. It would be terribly misleading."

Why is it that some weeks a book that has never before appeared on the list is catapulted to the top?

"Because people are just waiting for authors of reputation to publish their next book," said Wright.

Carl Lennertz, the director of the Booksense program for the American Booksellers Association, has another view. He believes the New York Times list can be manipulated. Everyone in the industry, he said, knows when big-name authors' books are being published, and the publishers coordinate delivery so the books will arrive at all bookstores around the country on the same day.

"The new Harry Potter book (by J. K. Rowling) is coming July 8," said Lennertz. "Everybody knows that. So people call and pre-reserve copies. Others come running in on the first day." This ensures that the book will be listed high on the best-seller list, resulting in more publicity and sales than ever.

Just over a year ago, Lennertz organized a Booksense Best-Seller List, which has received excellent support from independent booksellers. Many booksellers, he says, now prefer it to the New York Times. "We have 350 independent stores reporting to us each week, and we weight all stores equally. The King's English (in Salt Lake City) counts as much as a small store in Ohio."

Lennertz asserted that only 100-150 independent booksellers now report to the New York Times. That is a result of a backlash against the Times' decision to sign an exclusive agreement with Barnes & Noble in the mid-1990s to link Web sites and direct online sales to that chain. He said half of the independent booksellers who formerly sent sales figures to the New York Times stopped doing so.

Tony Weller, who owns and operates Sam Weller's Bookstore locally, says he stopped reporting to the New York Times at that time.

But Wright says, "Booksense is out to do the chains in. When we

put our best-seller list on our Web site, we included a place where you can click on Barnes & Noble and buy the book. After all, this is the electronic age." Wright denied that catering to one book chain brings the New York Times list under suspicion.

Lennertz also said the New York Times list "is pre-weighted to books that are already big. If there are a lot of copies of the book in the stores, that book is likely to be high on the list. The New York Times also includes wholesale reorders with sales out of the stores. That's why some books can be high on the list in spite of being sold out in the stores."

More than 25 U.S. newspapers are now subscribing to the Booksense list, in addition to C-Span, U.S. News and World Report and The Christian Science Monitor. But, said Lennertz, "The New York Times list is still the list of record. No question about it."

At the same time, he is hopeful that more publications will utilize the Booksense list, making it competitive with the New York Times.

Maybe a grain of salt is in order.

E-MAIL: dennis@desnews.com