BACK WHEN he was governor of California, Ronald Reagan unveiled a work-for-your-welfare scheme meant to drive wastrels from the rolls and turn the remaining recipients into contributing citizens. Welfare experts attacked the idea as unworkable if not downright cruel, and in fact the program never did work very well or produce measurable savings. Now, more than a decade later, a work relief program is about to be reintroduced into California with strong bipartisan support. This time the experts are saying nice things about it. Why the changed reviews?

One reason is that the political tenor of public debate has changed. But views have also been changed by practical experience. Experimentation with work/welfare programs has been almost continous over the past decade, and has produced successful programs. Massachusetts, for example, is enthusiastic about its ambitious welfare jobs-and- training program. One important lesson has been not to expect too much in the way of welfare savings.

Herding unwilling welfare recipients into ill-supervised work settings not only generates contempt for real work, it also undermines the morale and disrupts the efforts of regular government workers. Getting people to do useful work and move on to permanent jobs requires supervision, training and other services -- which the California program will apparently provide at a modest level. Coming up with substantial numbers of jobs for recipients is also a problem. There are plenty of useful things to do, but money for needed supplies and supervision may be scarce. Regular workers are also understandably fearful they will be replaced by unpaid welfare workers -- a situation that public unions say is already happening in New York and other areas.

But experience has also shown that the motivation and abilities of welfare recipients should not be underestimated. Even with no work requirement, as in Massaschusetts, work programs have typically had more applicants than they can handle. Welfare mothers, moreover, have always been among the most sucessful participants in work and training programs. The real test in California may not be whether the state can force welfare recipients to participate, but whether it can provide real labor market help to the many families that will seek it.