J. Rupert Picott, executive director of an organization that has promoted Negro History Week sice 1926, stared through dark-rimmed glasses as he searched for a phrase to make his point.

"One week is just not long enough to honor black achievement."

Picott, executive director of the Association for the Study of Afro-American Life and History, said his association has worked, since the Bicentennial, to replace Negro History week with something called Black History Month.

"It is an idea that has caught on like wildfire," explained Picott, 63, who holds a Ph.D. in education from Virginia Union University.

Pulling out a bundle of letters from U.S. governors and mayors proclaiming February Black Month, Picott proudly added: "You don't hear people talking about Negro History Week anymore."

One recent convert, who now marks Black History Month on his calendar, is President Jimmy Carter. The President recently invited members of the association to the White House to join in honoring the creation of Black History Month.

The association, which has offices at 14th Street and Rhode Island Avenue NW, claims a total membership of 25,000 divided into 139 chapters across the country. Picott says members of the organization have mailed letters, made phone calls and sold Black History Month to everyone they could collar.

"Negro History Week," explained Picott, who once served as assistant director of membership for the National Education Association, "did not give organizations enough time to sponsor activities and celebrate the achievements of black Americans."

The observance of Negro History Week was originated in 1926 by Carter G. Woodson, a noted black historian and a founder of the association.

Woodson, who died in 1950, placed Negro History Week in the month of February because it includes the birthdays of Frederick Douglass and President Abraham Lincoln.

Picott said his organization, now housed in a building called the Carter G. Woodson Center, started in 1915 to study black history and promote black achievement.

Part of their efforts this year have been devoted to expanding the association's black history kit, which sells for $19.45.

The purpose of the kit, he said, is to give educators -- and those interested in black history -- a foundaton on which to plan programs teaching black accomplishments.

The kit includes information about black political leaders, nurses, artists, inventors, families, monuments, coins and poetry. It also profiles a wide spectrum of important blacks from abolitionist leaders to ambassadors, as well as pictures black political figures, including Mayor Marion Barry.

"The kit has been very well accepted for several years as a supplement to black history," said Picott, who edits the material.

Since the association began, the organization has produced two quarterly publications, the "Negro History Bulletin" and the "Journal of Negro History." These scholarly works focus on details concerning black Americans and their accomplishments.

This month, the association is also publishing a book about a black doctor who graduated from Howard University and practiced medicine in New Jersey.

The book, called "Medicine, Motherhood and Mercy," is a biography of Dr.

Lena Edwards and discusses her contributions to medicine.

"We chose Lena Edwards because she has been a leader in medicine and has helped people without cost," said Picott.

Picott, who added that the association's efforts to promote black achievement are a year-round activity, explained that his organization is also responsible for placing historic markers where late black leaders were born, raised or worked.

He said the organization -- funded through contributions and membership fees ranging from $12 for students to $500 for life members -- has placed 101 markers honoring the achievements of blacks. One of those markers is located in the Northeast Washington National Trade and Professional School for Women and Girls, Inc. founded by Nannie Helen Burroughs, a prominent educator.

The most important achievement of his organization, however, is the recent creation of Black History Month, Picott said.

"We are pleased beyond words," he said, "about how the idea has caught on in the past five months."