''Living history,'' which recreates historical settings to simulate past periods, flourishes at museums in the United States and Canada. Despite its popularity with the public and the scholarship that underlies it, some historians and museum directors are wary of it. Then, too, no matter how careful the planning, unpredictable happenings can dispel without warning the illusion of life in another epoch.
Costumes, character impersonation, and period speech are the stock in trade of guides in living history settings. Guides perform typical tasks and demonstrate crafts to show how tools were used. Sometimes visitors try the crafts or tasks, a technique borrowed from open-air and children's museums.
Highly sensory, living history provides authentic sights, sounds, tastes, and smells, at least the pleasant ones like lavender or mint growing in the garden. At some sites, either scripted or ad-lib docu-drama is enacted to convey what life was like for our ancestors. Exhibited objects, often copies rather than originals, are just one part of the whole.
''Lots of people use living history in one form or another,'' says Susan Schreiber, assistant director of the American Association of Museums in Washington, D.C., ''but I've never liked it myself. It's a hypothesis, and to me it always suggests a stage set.
''From the standpoint of research, though,'' she adds, ''it contributes a lot to what scholars understand. Without back-breeding of animals, scholars couldn't be sure how much food a beef provided 200 years ago. They really wouldn't know what it was like to live when work had to be done according to the time of day or season.
''When it's well done,'' she points out, ''it takes a tremendous investment for the research.''
She cites Plimoth Plantation, the re-created 1627 Pilgrim village in Plymouth , Mass., and Mayflower II, in the town's harbor, as examples of sites that have made effective use of living history for museum interpretation.
''Both make sophisticated use of character impersonation,'' Ms. Schreiber says.
''We try to match the personality of the guide with that of the person he portrays,'' explains Rosemary Carroll of Plimoth. ''Once selected, the guides receive intensive training. First they have to learn all about the period - politics, money, religion, food, medicine, child-rearing, and more. Then each guide has to learn all about the individual he will impersonate. We have prepared manuals with this information to get them started, but they spend time in our library, too, with our sources.''
Jim Baker, research librarian at Plimoth Plantation, traces the beginning of living history back to 1873, when the Skansen outdoor museum near Stockholm was founded. By 1891 Skansen had a number of farm buildings, each of which constituted a ''walk in'' exhibit where guides demonstrated crafts and tools.
But beyond Scandinavia, Europe remained skeptical about this kind of popularization.
'In general, Europeans still look down on living history as frivolous. They compare it to historical novels,'' Mr. Baker says. ''There's a reason why they think the way they do and why we do it our way,'' he concedes. ''Here at Plimoth we use reproductions, so for us ad-lib dialogue is congruous. We can offer a real hands-on experience, because we can replace whatever gets damaged with another replica. But in Europe, where museums preserve and display authentic objects, they can't afford the risk of breakage. A guarded and structured museum tour precludes the kind of visitor involvement we encourage.''
In the United States, Colonial Williamsburg in Virginia, Conner Prairie Pioneer Settlement near Indianapolis, and Old Sturbridge Village in Massaschusetts were among the first to adopt living-history techniques. Some military garrisons used parts of the technique even earlier.
From its opening, Williamsburg has costumed its guides to match the 18 th-century settings in which they serve. They are also free to answer visitors' questions which reach into the present.
By contrast, character impersonators at Plimoth or Connor Prairie must feign ignorance of events ''still in the future'' for the people they represent.
Conner Prairie has created fictional families to help visitors understand the attitudes and concerns of Indiana pioneers. ''Dr. Campbell and his wife'' have moved to the settlement from Lexington, Ky., for example. His wife usually finds an opening to complain that life in rural Indiana seems dull after the cultural advantages she enjoyed in Lexington. The doctor, through his ad-lib conversations with visitors, imparts information about medical practices and home remedies in the early 19th century.
Another Conner Prairie character represents a widow. One of the few occupations suitable to someone in her situation at that period was a seamstress.
Visitors, as well as guides, role-play at Conner Prairie. When they are seated on the hard benches in the schoolhouse, the schoolmaster is likely to ask them how many states there are in the United States. The ''smart'' pupils count the stars on the flag at the front of the room to come up with the correct answer.
''But we have finally resolved the limitations of restricting guides and visitors to one brief moment in history,'' says Polly Jontz, director of Conner Prairie. ''In most of our buildings, guides belong to the year 1836. But this June we opened two additional buildings where guides speak in the third person and can give the broader history of Indiana settlements.''
As at Williamsburg, correctly costumed potters, blacksmiths, and woodworkers make the replicas displayed at Conner Prairie. But behind every replica is an authentic article belonging to the correct historical period.
''Living history has its merits, but it's quite artificial. When I visit (Colonial) Williamsburg, I can never get convinced that I'm in the 18th century. It's just too clean,'' says Dr. Frederick J. Thorpe, director of the historical division of the National Museum of Man in Ottawa. ''At Fortress of Louisburg National Historic Park in Nova Scotia, guides accommodate English-speaking visitors by using English. But that's not authentic. Certainly at this 18 th-century French fortress, French was the language used.''
The Museum of Man is not at present considering switch-ing to living history. ''We have the occasional temporary exhibit where we might demonstrate a craft,'' Dr. Thorpe says, ''but I think the collective view is that there are enough museums that do this.
''However,'' he concedes, ''we are moving more and more toward putting objects into context through designing period rooms, workshops, and so on.''
Pamela Gibb-Carsley, development officer with the Canadian Museum Association , estimates there are ''at least 40'' museums spread across Canada which present living history.
Black Creek Pioneer Village near Toronto, Kings Landing Historical Settlement at Fredericton, New Brunswick, Western Development Museum in North Battleford, Saskatchewan, and Doukhobour Village Museum at Castlegar, British Columbia, all use living history as an interpretive technique. Even Yukon Territory has as least one historic site - Harrington Store in Dawson City - which tries to propel visitors backward into its heydey.
Visitors need a careful orientation to help them pretend they're in another era, living-history museums have learned. Even well-designed orientation films and presentations can't always overcome a visitor's reluctance to role-play.
Nor is it possible even for the most astute program director to foresee every hazard. During an enactment of the Virginia House of Burgesses one night at Colonial Williamsburg, when the audience had been invited to participate as ''members,'' a student in the audience rose and gave a tongue-in-cheek recital of Patrick Henry's ''Give me liberty or give me death'' speech just before the actor impersonating Patrick Henry could deliver his impassioned lines.
Alice Reed of Indianapolis says she went to Mayflower II with a willingness to pretend. She says she cannot blame the program or staff for her failure to be transported back into the 17th century.
''I really wanted to play my part and ask 17th-century questions of the costumed guides,'' Mrs. Reed says. ''But all of my fellow visitors that particular day were Japanese tourists. It's pretty hard to have the Pilgrim experience feel authentic when your 'fellow passengers' from Holland to Massachusetts are Japanese.''