Family life is the longest school human civilization ever devised. There's no graduation date, and ''family school'' is never out — unless one fancies the calling of a hermit or cares nothing about severing those ties that are supposed to bind. Age makes little difference, either. Everyone's forever teaching and forever learning.

I have heard old teachers declare at the end of their careers that they learned more from their students than they ever could have imagined.

Same with parents. Having had their babes for teachers, they'll declare they are the richer for the experience. (My suspicion is aging parents grow this magnanimous only after time has dimmed the likelihood of said children returning to the nest. There's only so much learning one can fit in a lifetime.)

Since educators started talking about ''value-added education,'' measuring growth students make from one year to the next from all the effort that goes into schooling, it has seemed to me that parents, also, need a way to score value-added points in their efforts to raise upstanding citizens. At least, tracking the value added from year to year would keep them persevering through those rough stretches when it looks as if little they say or do has left an imprint.

Not to press the school analogy too hard, but in recent years, so much of public discussion has been about accountability, about holding people responsible for outcomes of education, whether the type pursued in schools or the teaching that occurs within the families. More often than not, the targets of demands for accountability are educators and parents, which is fair enough. After all, we all have a vested interest, and parents more so than anyone, in the outcome of the learning that occurs in both settings.

The rationale behind value-added assessment is quite persuasive. Under rising pressure to attain certain standards of achievement, many educators are demanding credit for every possible accomplishment. (Who can blame them? Laws such as the federal No Child Left Behind threaten stiff penalties if they don't make passing grades.)

Educators argue, for example, that achievement tests don't measure the degree of learning and the progress students can make over a period of time, even when their accomplishments don't rise to a passing grade on achievement tests. Every positive movement of the educational needle is value-added learning. It may not amount to passing, but it represents growth all the same, the argument goes, and it deserves credit.

Maybe parents, too, could claim credit for effort, argue value-added learning, when bone-headed children get into trouble? Just a thought.

A legislator or a judge gets all in a huff about a teenager skipping school and before you know it, someone wants a law to arrest parents for rebellious kids who decide to play truant. So much of the blame for an offspring's behavior can be reflected back on parents, sometimes it is all we can do to scream: We did the best we could!

Unfortunately, in this age of accountability, a desperate cry like that wouldn't cut much ice. No one has to tell parents who take their responsibility seriously that children have an unerring instinct for thwarting their best teaching efforts. Or that the course of raising reasonably responsible citizens never runs straight or smooth.

One example. Among the most critical skills parents are expected to teach in the family school, I think the most difficult is helping children develop the art of making good judgments. It is a basic quality that runs the gamut of personal and social decisions. It could be about picking friends or selecting clothes or deciding where to go or what principles to respect.

If any part of a family's responsibility is made for value-added consideration, developing good judgment must be it. It is a slow-growth quality, measurable by slight increments, the tests and passing standards for good judgment infinitely varied.

How do you judge a 20-year-old, say, who is smart enough for college, who still thinks it may be great fun to test the limits of an elevator by cramming himself and as many of his buddies as would join him? Would a parent get some credit for all the lessons in judgment those many years before?

I've come to appreciate that when parents say they've learned a lot from their children, most times what they mean is that they have learned patience. And they've learned that where judgment is concerned, hope is a renewable resource: Every year is a step toward a passing grade.