"Harlan County, U.S.A," opening today at the Outer Circle 2, suffers from some makeshift structural devices and occasional lapses of judgment, but it's an ardent, absorbing work of partisan documentary film-making.

Nominated for an Academy Award as the best feature documentary of 1976, the film represents the culmination of four years of preparation, shooting and editing supervised by a young woman named Barbara Kopple, who resolved to chronicle a strike for union recognition by coalminers in Brookside, Harlan County, Ky.

The strike began in July 1973 and lasted 13 months. The settlement, by which the mine owners, the Duke Power Co., agreed to recognize the United Mine Wokers of America as the bargaining agent for the Brookside miners, appears to have followed rapidly a shooting incident in which one of the strikers was killed.

Kopple, a former VISTA volunteer committed to films documenting labor struggles and advocating social reform, became acquainted with leaders of the reform movement within the UMW, including the current president, Arnold Miller, in the early '70s. She produced a short film about their activties in 1972, and she served as a crew member on such pictures as "Winter Soldier," "Gimme Shelter" and "Hearts and Minds."

By the time the Brookside strike began, Kopple had acquired the experience, connections and conviction necessary to cover it. However, the prolonged nature of the strike also prolonged the production, which Kopple sustained by appealing for grants and loans from a large number of foundations, churches and indivduals. She has emerged with a stirring, revealing testament to the courage, tenacity and dignity of Appalachian men and women whose livelihood depends on coal mining. At their best Kopple and photographer Hart Perry bear unassuming, expressive witness to the experiences, aspirations and abiding grievances of the Brookside miners and their wives, who organized auxiliary strike actions. "Harlan County" feels honestly, rather than opportunistically, humble in the presence of its subjects.

It's possible that the structural problems in the film have been caused in part by the same intimacy that accounts for much of its human immediacy and emotional conviction. Involved with both the new union leadership and the Brookside strikers, Kopple may have complicated the film unnecessarily by trying to incorporate too many developments. One is left with the impression that Koppie was reluctant to finish the fim, that she kept wanting to add foot-notes and bulletins.

There's so much updating in the closing stages that the clarity of the main events is blurred. Kopple seems toi be struggling to emphasize a point she has already made - that the miners' problems will not automatically vanish with either the end of the strike or union recognition.

The ongoing, incorrigible nature of labor-management conflicts in this industry and part to the country - nick-named "Bloody Harlan" in the '30s - is established vividly by the way the participants look and the things they have to say. Despite her obvious partisanship, Kopple makes some effort to let the strikers' antagonists have their say and to indicate that hostilities and suspicions exist among the strikers themselves.

While Kopple seems to have enjoyed greater access to the miners' wives than any other concerned group - and may have magnified their role as a consequence - she also demonstrates surprising rapport with a mine foreman named Basil Collins, the most obdurate strikebreaker. Collins felt relaxed enough with Kopple's equipment around to act naturally and say his piece. He's convinced that unions are out to wreck the country. Since Kopple also reveals the deep distrust among miners who feel the union has betrayed them in the past, Collins' viewpoint can't be dismissed out of hand. It's an integral part of the setting and culture.

Kopple's worst stylistic habit is superimposing songs over sequences that don't need them as either commentary or transition. It's almost as if she got accustomed to living and working with a constant accompaniment of folk songs and/or union songs and couldn't do without them, even when they become obtrusive. They're especially superfluous in sequences depicting miners undergoing physical exams for lung disease. Typically, Bargara Kopple miscalculates whenever she seems to fear that her eloquent raw material may not be eloquent enough.