Standardized test scores in education are like a physician's stethoscope and thermometer: they can't render a complete medical analysis or a single cure, but they can give some important indications of a patient's health. Similarly, this year's much improved test results for D.C. students can't tell the whole story of public education in Washington, but they have offered the city an encouraging diagnosis and promising prognosis for its schools.

The median scores of our third and sixth graders exceeded national norms in basic skills for the first time since systemwide testing began in 1978. The ninth and eleventh grades, while still falling considerably short of the national marks, showed substantial gains, particularly in reading, math and science.

These improvements came about without the aid of any magical, overnight reforms; and they are not a fluke, a never-to-occur- again phenomenon. This is the sixth consecutive year in which test results have risen. The gains can be attributed to a complex series of events, including the adoption of a standard, high-expectation citywide curriculum in 1979; the provision of enough money last year to pay for smaller classes and extra instructional help; and the dogged determination of teachers and principals to rally student learning with tutors after and before school classes, instruction in practical test- taking skills and, most important, the self- confidence to succeed.

A pattern of rising achievement--and test scores are probably the most visible sign of that increase--sends some significant messages not only to parents and children, but also to the public at large. In Washington's case, the communication is clear: a large, predominantly black urban school system can-- and does--work. While this is not a particularly startling fact to countless educators whose careers have been based on a belief in the power of education, urban school success does directly counter some long-held public notions that schools can do little to overcome a backdrop of poverty, decayed cities and cultural disadvantage.

Heightened academic achievement should also tell our city that its investment of tax and personal support has been sound. The school system anticipates even greater dividends to come. Teachers are continually asking students to become "results-oriented"-- and residents are justified in requesting the same of their schools.

The test-score message for teachers and school administrators is twofold. First, it validates a year of diligent work and sets a tone for the coming school year. Second, student gains in standardized testing cast a harsh spotlight on our shortcomings--which can serve as the most powerful motivation to reach for still greater accomplishments.

Our secondary schools, for example, have some sound footing on which to make more gains. Next year's senior class will be the first to graduate under a set of beefed-up course requirements in English, math and science. A computer-assisted remediation program, begun this past year at Springarn High School and showing measurable success, will be replicated at four additional high schools in the fall.

Five career-program ventures we have begun in partnership with private interests are demonstrating that kids are showing more understanding of job requirements and are striving for academic excellence as the means to reach their goals. We will be enlisting the help of more businesses in these endeavors and will be opening a sixth career program with a major corporation next year.

At the junior high level, teachers and principals will be working with the American Academy for the Advancement of Science to strengthen our science instruction. Howard University as well as a satellite network of six other school districts around the country will be using instructional television to share proven classroom strategies with our teachers.

The test scores also allow our educators to pinpoint the schools experiencing success and those that need help. Next year, we will be analyzing the elementary and secondary schools that require assistance, sending teams of teachers and other instructional experts to assist some schools and to find out what is working well at others.

The schools' guiding theme next year is "Improving the Quality of Teaching and Learning." It's not that this hasn't been the essence of our mission in the past, or that we haven't shown a great deal of improvement this year. But we know--perhaps better than anyone--that a measure of success in 1983 can be transformed into a record of greater achievement in 1984.