Evidence is growing that Americans view rape as a much more serious but controllable crime of violence than they did a decade ago. And many, once prone to blame the victim for provoking the action by dress or behavior, are now apt to see the offender as primarily responsible.
Thus the news several weeks ago that a young woman had been gang-raped in a New Bedford, Mass., bar - as some onlookers encouraged the incident and none reported it to police - struck some who monitor the progress in this field as a giant step backward. Particularly so, since there has been at least one other recent instance (in Boston's Charlestown neighborhood) in which witnesses did nothing to halt the crime.
''You'd really have thought we'd come further than that by now,'' observes Jean Garrison, deputy director of the federal government's National Center for the Prevention and Control of Rape (NCPCR).
But in many ways the ensuing public outrage - as measured by the prompt closing of the bar by its proprietors, the steady flood of sympathetic phone calls pouring in to the local women's center, and the candlelight vigil by 2,500 protesters near the New Bedford City Hall - may say far more about society's prevailing view on this important subject than the incident itself.
There are signs that a significant shift is under way in public attitudes about rape:
* Over the last decade, prodded in large part by the women's movement, hundreds of ''rape crisis centers'' have been started by volunteers around the country. Although recent funding cutbacks have forced some closings and mergers, the estimated total is still an impressively high 500 to 800. Most are busier than they care to be.
''We're working at almost capacity caseload,'' notes Cindy Shirling of Pittsburgh Action Against Rape, where the staff of seven counselors last year handled 1,500 new clients. Yet for many centers the original focus of victim counseling and support has been broadened to include training professionals who work with victims and offenders and educating citizens and students on how to avoid rape and deal more intelligently with it.
Police and hospital treatment of victims on the whole tends to be more sensitive than it was a decade ago. And crisis center personnel currently are invited to speak before a much wider array of forums - from scouting and community groups to religious organizations and schools. ''Basically we'll speak to anybody who will let us in,'' says Marjorie Burton, program coordinator of a county-sponsored rape crisis center in St. Paul, Minn.
* Most states have made major reforms in laws concerning rape in the last decade.
Michigan was the first to pull together scattered laws into one comprehensive sexual assault statute in 1974. Considered a model by many other states, it specifies in detail four degrees of related crimes. Though some have argued such pooling could lead to more plea bargaining, a study coauthored by Jeanne Marsh, a social psychologist with the University of Chicago, indicates that convictions on the most serious charge of forcible rape went up rather than down after the legal change.
Laws have also been revamped to shift more of the responsibility for rape away from the victim. The great majority of states have passed rape shield laws in the past few years which protect the victim from being quizzed on her past sexual history unless it has a direct bearing on the case. Some states have also passed - and others are considering - more controversial legislation which would allow wives under certain circumstances to charge husbands with rape.
* Reporting of rapes, particularly to rape crisis centers, is up. ''I see that as the most consistent forward gain in this field,'' says Joyce Williams, a sociologist at Texas Woman's University who has conducted extensive studies of public attitudes on rape.
Yet the estimated 81,536 rapes reported to police in 1981, though almost twice the figure of a decade ago, may only represent a small percentage of the number of actual rapes in this country, according to Federal Bureau of Investigation officials who garner such statistics. Rape is still regarded as one of the nation's most underreported crimes. Because of the considerable embarrassment still involved in the reporting process, many rape crisis centers confine their role to supplying information, rather than urging victims to report incidents to police.
* As recently as five years ago, only 1 rape complaint in 4 led to an arrest and 1 in 60 to a conviction. But the proportion of arrest and convictions in some jurisdictions now is markedly up. In Philadelphia, for instance, where the district attorney's office set up a special unit in 1978 to work exclusively on rape cases, convictions have since doubled to 80 percent of the cases filed. Assistant district attorney William Heiman, chief of the rape unit, credits changing public attitudes for much of that success.
''We can monitor the attitude change by jury verdicts, and we're seeing a definite improvement,'' he says. ''Support is growing for the concept that rape is a crime of violence no matter what the victim was doing - whether she was into drinking or drugs, for instance, before the incident. We're winning cases we used to lose 10 years ago.''
Most experts in the field view the changes that have come as a result of a slow but steady process of public education.
''More than any other group, I would say that rape crisis centers have done the most to raise the national consciousness on this subject,'' says Nicholas Groth, director of the sex offender program for the Connecticut Department of Corrections and a member of the advisory committee of NCPCR. ''They were established by volunteers because victims were looking in vain to professionals for help.
''The centers, police, particularly parole and probation officers, and nurses were really the first to get involved,'' says Dr. Groth. ''Then those in social and child-protection work became interested. Slowly, within the last two years, there's been a little more response from teachers, wanting to know what to teach about the subject and what to do if a student is victimized, and from the clergy , who want to become more knowledgeable to counsel more effectively. The groups we've had the least success recruiting have been judges and psychiatrists.''
But most researchers who focus on public attitudes about rape insist that, significant as some of the progress has been, much more is needed. They say acceptance of varied myths about rape, stemming in large part from continued stereotyping of the characteristics and roles of both sexes, is still widespread.
A 1980 sampling of public attitudes in Minnesota, for instance, found that more than half of those queried said they thought most rapes were the result of the victim's promiscuousness - that she in effect deserved what she got because of where she was, how she was dressed, or what she was doing. The majority said they believed those reporting rapes were trying to get back at men with whom they were angry or to cover up illegitimate pregnancies.
''It all goes with the standard sexual stereotyping of men and women as adversaries and of sex as an exploitive thing rather than as a basis for cooperative behavior,'' says Martha Burt, director of social service research at the Urban Institute in Washington, D.C., who conducted the study.
''There is still a tendency to see rape as a part of sex rather than as a decision to make a violent attack as in a mugging. And we found that if people believed one myth about men and women, they were more likely to believe the whole set. . . . That's the reason attitudes are so hard to change. It's sort of like changing a whole world view.''
Studies of convicted rapists have shown that many of them also hold the same sexual stereotypes, and often view what they did as justified under the circumstances.''
I think we still have a long way to go with public attitudes,'' says Dr. Williams of Texas, who has conducted a number of attitude studies. Many queried in her surveys also said they felt that rape victims generally ask for and deserve what they get. ''Rape does not just happen to ladies of the night who walk the streets in short skirts,'' counters Francine Stein, executive director of the Illinois House of Representatives' Rape Study Committee.
Many Americans blame the country's rape problem on factors such as: the popularity and availability of pornographic and violent literature and movies; the emphasis on sexual attractiveness in fashion and other advertising; and an apparently more relaxed attitude toward premarital sex.
Most experts agree that such patterns do play a role. But some who deal daily in this field insist they are not an excuse for commiting what is in fact a violent crime.
''Many people still have to be convinced that rape is an act of violence and a power thing rather than an act of sex,'' says Ms. Stein. ''We have to work harder at educating the general public to the fact that we do not do violence to other human beings.''
A Department of Justice advice booklet on rape observes: ''In over one-third of reported cases, the rapist is an acquaintance, neighbor, friend or relative.'' Many victims are too embarrassed to report such cases.
Clearer communication between the sexes and a greater sense of freedom for men from peer pressure to prove their masculinity could do much to ease that problem, says Sharon Sayles, president of the National Coalition Against Sexual Assault. The coalition represents about 300 rape crisis centers, attorneys, and others dealing in services to rape victims.
Young women, says Ms. Sayles, need to be taught to be more forceful and convincing when they refuse an offer for sexual relations, while young men should be taught to respect the woman's decision. Smiles and other gestures which a woman may consider merely friendly need to be read more accurately as such by men.
''This notion that women are asking for rape and will submit . . . just becomes a convenient excuse for inexcusable behavior,'' says Ms. Sayles. ''Reasonable men who know this is a crime of violence must let other men know it will not be tolerated. Women have spoken out against this and started to change the laws to protect themselves. Men need to take some steps too.''
Many men, it should be noted, are doing much to try to curb the problem. Though women's groups often take the lead in initiating state legal changes, male legislators usually play a key role in passing them.
And Nicholas Groth, author of the book ''Men Who Rape,'' says there is a need for more compassionate and constructive help from the public for those offenders who want to change their ways. Not many, once caught, repeat the crime. Yet employers are often wary of hiring anyone ever convicted of a sexual assault.
''People often don't differentiate between the person and the behavior they despise,'' he says. ''Some offenders have redeeming values, are troubled by their behavior, and want to change. Yet the public tends to find it easier to lump them all together rather than recognize the complexities of the situation. . . . I think people have to be held accountable for their mistakes, but they also need to be helped to change.''