Alexandria school officials proposed a plan last night to improve minority achievement through tangible methods such as extra tutoring and special awards assemblies as well as the general goal of raising expectations for minority students.

The issue of minority underachievement in Alexandria first drew public notice last summer when Superintendent Robert Peebles released the breakdown of Science Research Associates test scores by racial group, showing disparities as wide as 48 points between the scores of black and white students. The Alexandria School Board made improving minority achievement its major goal for the 1985-86 school year.

"I am convinced that the attention that has been paid to this subject means we are paying attention to instruction for all kids," said Peebles. "I believe it is going to pay dividends."

Among the broad goals of the plan, presented in draft form last night, are to improve minority students' motivation, communicate more effectively with their parents, raise expectations that administrators, counselors and teachers have of minority students and increase public knowledge of minority students' accomplishments.

Specifically the plan calls for tutoring, hiring more minority administrators and holding assemblies to display the work of minority students. Another proposal is to pair junior high minority students with adult mentors who will help them choose courses, decide on careers and plan for college.

Robert A. Hanley, director of secondary education who will oversee the plan, said future versions will include more timetables and specifics about how it will work.

In another report presented last night, English curriculum assistant Patty Claussen told the board that the present method of "phasing" high school English classes, or placing students in four groups based on achievement, is a sound way to teach, but urged officials to use more test data to determine where students should be placed.

That report was prompted partly by some critics of phasing who argued it discriminates against minority students. Of 500 tenth graders, 83.6 percent of those in phase 1, the lowest-achieving group, were black and 9.8 percent were white. Phase 4, the highest achievers, included 75 percent white students and 10.7 percent black.

The report concluded that socioeconomic factors accounted for the heavy black enrollment in the lower phases. "Many of our students come to school from homes in which books, ideas and learning are not stressed . . . for many the vistas opened up in school are almost a foreign experience and in the beginning they do not feel right, and they do not immediately take," it said.

Teachers must continue to push such students, the report said. "A school system cannot afford the luxury of emotionalism . . . . It cannot afford for anyone to make the assumption that because these students have not, they cannot."