If you are under the impression that The Post has run a lot of news series in the past several weeks, you are right. By actual count, there have been 12 series published between Thanksgiving week and New Year's week, or almost two series per week. And my yardstick toted up more than 5,000 inches of type and art, an amount approaching the wordage of an average complete novel.

How many of you read every series -- from "Africa: The Hungry Continent" to "Home Rule: The First Decade" -- published during the seven weeks? Okay, let's make it easier: How many of you read even one complete segment of any one of the series from beginning to end? All right, how many of the dozen series can you name beyond the two I have already mentioned?

Editors at The Post defend -- even brag about -- the series of series. They believe the two running this week, China's "One Couple, One Child" by Michael Weisskopf and "The Next Round at Geneva," provide definitive information, as well as a context to and an opportunity for reexamining the subject under discussion, things not readily available in daily coverage focusing on spot developments, staccato charges and counter-charges.

Leonard Downie Jr., managing editor, argues that the holiday season is a good time for a series. "There is less news, Congress has gone, everything shifts into low gear. People have more time to read the paper. They are off from work more."

As for inundating readers with lengthy pieces, Mr. Downie is not dismayed. "I don't really expect a series to be read word for word. They serve different publics. Those who are interested in a series will read every word, and they call and thank us for running the articles."

Some news sources complain that series sop up news space and make it harder for them to get in stories about their own activities, but Mr. Downie denies any connection. He said there is special space set aside for series in order to give readers a "closeup, detailed look" and to "focus people's attention on matters of importance."

He acknowledges that some series could have been shorter. The four- part series by Chip Brown, "Whoops," on the Washington Public Power Supply System, is one, although the bond failure was "an object lesson that what we do in the short run may be wrong in the long run."

But did the well-written series about an event that occurred years ago on the West Coast warrant more than 850 column inches? Could it have been trimmed to a single Sunday Outlook section piece? Or a Sunday Magazine article? Are there magazine articles infiltrating the daily paper?

Suppose there had been only one article, space bank or not. Would there not have been a better chance for some news that was left uncovered to have made it into the paper? Would there have been more room for texts of important news conferences or other major policy statements?

Mr. Downie says that while The Post is not seeking to become "an elite newspaper of record" there is a determined effort to use more full texts, and space has been earmarked for this in 1985.

There is no doubt that reporters like the visibility, prestige and prize- winning possibilities created by publication of a series, and editors enjoy the attention that a series attracts to their sections. But I question whether 12 series in seven weeks is not overdoing it. The series traffic was so heavy in the holiday weeks that often readers were confronted by more than one series on the same day.

And now for those readers who may be wondering what topics were offered to stretch and fill their minds while they may have been shopping, here's the list: "Africa: The Hungry Continent"; "The Dealmakers"; "Whoops"; "Lean, Green and Mean: The Army of the '80s"; "Riding the Red Line: Four More Stations"; Nicaragua's "Secret War"; "The Roots of Biotechnology"; "Inside the Geographic"; an eight-part series on college basketball, "The City's Game"; essays based on a British diary on the Falklands; "Fundamentalism: The New Old-Time Religion"; and "Home Rule: The First Decade."

If you read them all, you're a prime candidate for the managing editor's Blue Ribbon award. It arrives in seven pieces, one for each day. If you didn't make it through a complete segment of any series, you're a prospect for the Ombudsman's Truth in Reading citation.