WHAT ARE the qualifications of a good judge? Wisdom, compassion and courage are some of the qualities that come most readily to mind. But they are also the hardest to measure in advance. Practical experience, on the other hand, is easier to gauge - once you decide what kind of experience is relevant. But because the Carter administration and the American Bar Associations judicial selection committee can't even agree on what kind of experience ought to count the most, a seat on the federal district court here has been vacant for six months.

The administration wants to nominate Carin A. Clauss, the Labor Department's top legal officer, to fill the vacancy. The ABA's committee, which has screened judicial nominees for the last 25 years, has refused to give its blessing because she has had no courtroom experience.

The published standards by which the ABA measures judicial candidates require that it rate as unqualified any candidate who lacks "substantial trial experience" unless other qualifications are so exceptionally high that a limited amount of courtroom work seems adequate. The Carter administration is arguing that a lawyer who has spent years enforcing federal laws and supervising both the trial and appellate work of a major department ought to be able to meet the experience criterion of the ABA.

As a general proposition, the ABA's standard is right. The federal district courts are no place for judges who have to learn how to conduct trials before they can carry their full share of the load. The standard was created to provide at least one objective qualification that could be used to keep political hacks off the bench, and it has been highly useful in doing just that several times in the past two decades. The ABA has overreached only in applying that same standard to appellate judges where actual trial experience is considerably less important.

Whether Miss Clauss's experience justifies making an exception in her case is something that the Carter administration and the ABA committee will have to decide - and they should do so without further delay. In reaching a decision, they should also keep in mind that this is not a unique situation. The practice of the legal profession until quite recently was to tuck its first-rate females in the back rooms as much as possible and rarely let them out to go to court. As the pressure to get more women into the federal judiciary increases, so will the pressure to bend what is basically a good rule for trial judges - unless, of course, the administration and the organized bar can begin, as they should, to get some of those well-qualified women onto the appellate courts where their lack of trial experience is not so much of a handicap.