AS WOMEN MOVE in increasing numbers into jobs traditionally held by men, they have begun to question the validity of tests given to applicants for jobs that require physical strength. Two cases recently in the news illustrate the complexity of these questions.

The Army has announced a new policy concerning job classification and tests for physical strength. Each of the 350 military occupation specialties (MOS) was analyzed and rated from the standpoint of physical strength required. A "light" job, for example, is one that requires lifting a maximum of 20 pounds and frequent lifting of 10 pounds. A "very heavy" job requires lifting more than 100 pounds and frequent lifting of 50 pounds. All new recruits, male and female, will be given a strength-capacity test and assigned an MOS according to ability. Women who can perform the heavy jobs will get them; some men will be assigned to lighter duty.

This kind of test is sensible and fair and is, in principle, exactly what the women's movement has sought to achieve. Two big questions remain, however, Rep. Pat Schroeder (D-Colo.) wants to look carefully at each MOS to see if it has been properly classified. If a job is listed as "very heavy" when it is really "moderately heavy," recruits with less physical strength will be unfairly excluded from the job slot. Rep. Schroeder, reasonably enough, wants to be certain this will not happen. A related and more difficult problem for women in the Army is the policy that excludes them, because of their sex, from all jobs that are combat-related. There are 61 job specialties in this category, and they include assignments such as radar operation and vehicle repair that do not necessarily require physical strength. Neither the armed forces nor Congress appears ready to change the combat-exclusion policy, but many women continue to view it as discriminatory rather than protective.

Similar questions have arisen about job tests for New York City's Fire Department. In 1978, the first year in which women were allowed to take the qualifying examinations, 170 passed the written test but every single one failed the physical. One of these women challenged the validity of the test in court, and a federal judge ordered it to be revised so that it more accurately measured the physical strength needed specifically for firefighting. The old test, for example, required an applicant to lift 180 pounds and carry it down a flight of stairs. The new test calls for dragging a 140-pound weight. The all-male firefighters' union says the new test is inadequate, but it has been approved by the court. But here's the catch: the new test is only for women. Men who failed the physical cannot now qualify by passing the new test. The union is back in court with the legitimate demand that the same standard be applied to both sexes.

The law in the area of sex discrimination in employment is still evolving. When it comes to testing physical ability, the courts should require two things: that the test accurately measure the strength needed to perform the job and that the same standard apply to all applicants for the same position without regard to sex. Those seeking equal treatment can ask no more and should accept no less.