Barbara Adams Mowat, who was director of research at the Folger Shakespeare Library and co-edited authoritative editions of the works of Shakespeare. (Julie Ainsworth/Folger Shakespeare Library)

"What do you mean you edit Shakespeare? What do you do? Correct his grammar?"

She had been asked that question more times than she could remember, said Barbara Adams Mowat, former director of research at the Folger Shakespeare Library and co-editor of more than 40 editions of the Bard's plays and poems.

No, she was not a grammarian, she would answer. Her editing of Shakespeare came in the resolution of discrepancies between differing versions — hundreds of years old — of the same play.

Dr. Mowat died Nov. 24 at her home on Capitol Hill, only blocks away from the Folger Library, where she served 25 years on its literary staff. She was 83. The cause was cancer, said a son, William Mowat.

In 2010, Dr. Mowat retired from the Folger, where she had also served as director of academic programs and editor of the Shakespeare Quarterly since 1985. She was a former president of the Shakespeare Association of America.

But she was probably best known for her work over 20 years as editor with Paul Werstine of Shakespeare's works for the Folger Shakespeare Library Editions. More than 17 million copies of these books have been sold, according to the Folger, and they have become standard Shakespeare texts in American high schools.

Barbara Adams Mowat with some of the books she edited for the Folger Shakespeare Library Editions. (Julie Ainsworth/Folger Shakespeare Library)

In the 400 years since William Shakespeare's death in 1616, Dr. Mowat wrote in an essay in Folger Magazine, "editors have recognized . . . that we have nothing from Shakespeare but printed versions that often disagree with each other and that are filled with typographical and other kinds of errors."

Sometimes characters had different names. Puck, of "A Midsummer Night's Dream," was also known as Robin Goodfellow. In an early version of "Hamlet," the queen — Hamlet's mother and newlywed wife of the villainous King Claudius — is named "Gertrard," not Gertrude as she would become known.

"The more I work with Shakespeare texts, the more I become aware of the double pull on the editor of Shakespeare today," Dr. Mowat wrote in Folger Magazine.

She cited "the pull toward accuracy and consistency in editing and the often conflicting pull exerted by what I call 'readers' rights.' . . . Does one replace 'Gertrude' with 'Gertrard'?

"My co-editor and I decided that this character lived today as Gertrude, and to give her back her original name in our text would do too much violence to readers' (and audiences') rights."

Barbara Sue Adams was born Jan. 29, 1934, in Eufaula, Ala. Her father was head of the textile engineering department at Auburn University. Her mother was a homemaker who had a bachelor's degree in chemistry.

She graduated from Auburn with a degree in mathematics in 1956, then did graduate study on the philosophy of science in Innsbruck, Austria, on a Fulbright scholarship.

It was in Austria, she would later tell Auburn's Spectrum magazine, that "I discovered what I truly loved doing was reading and that I could actually make a living doing just that."

She came to the United States to study English literature, receiving a master's degree at the University of Virginia in 1961 and a doctorate in 1968 from Auburn, where she later taught.

She was "tiny but indomitable," said Gail Kern Paster, the Folger's director emerita, "with a terrier-like tenacity and a Southern charm."

In Austria, she married John G. Mowat. They later divorced.

Survivors include two children, William G. Mowat of Bellevue, Wash., and Elizabeth C. Lewin of Annapolis; two sisters; and three grandchildren.

From 1969 to 1980, Dr. Mowat taught at Auburn, then became dean of Washington College in Chestertown, Md., where she served for two years until joining the staff at the Folger. She wrote widely about the role of magic and the supernatural in Shakespearean drama — from the witches in "Macbeth" to lions in "Julius Caesar" and Oberon, the king of the fairies, in "A Midsummer Night's Dream."

With Werstine, Dr. Mowat edited 42 books that collected all of Shakespeare's plays and poems, but she made no claim that the job was finished.

In the Folger Magazine essay, she wrote, "We have abandoned, I think, the hope felt by many throughout the intervening centuries that someday editors will establish a definitive Shakespeare text."