Elementary school pupils again exceeded national norms on city-wide tests this year, while junior high school students held steady and high school students continued to score well below national averages, school officials announced yesterday.

D.C. School Superintendent Floretta D. McKenzie said this year's test results "reflect a continued overall pattern of steady improvement at the elementary and junior high levels, and points again to the need for continued and intensified work at the senior high level."

Eleventh graders, whose scores have not been close to national norms, declined by one month. Their scores, which were at 10th-grade levels in reading, mathematics and language skills, are a source of concern for school officials, McKenzie said.

"The 11th grade is the most difficult area to show improvement, with the exception of a few individual schools. We don't know all the reasons that there hasn't been more progress there, but we're looking into the situation. There's no question that the senior high schools have been the most resistant to our improvement efforts," she said.

Elementary school pupils maintained steady progress, exceeding norms by as much as three to seven months and junior high students inched a little closer to national averages, according to test data.

Eighth-grade scores exceeded the national norm in mathematics for the second year in a row, while again ranking below the norm in reading and language skills.

The Comprehensive Tests of Basic Skills is a battery of tests given in the eighth month of each school year to grades 3, 6, 8, 9 and 11, and the results are keyed to grade-level equivalents. For example, the national norm is 3.8 for the eighth month of the third grade and 11.8 for the eighth month of the 11th grade. The major parts of the examination cover reading, mathematics and language, but tests in science, social studies and reference skills are also given.

The D.C. test scores showed a range of achievement among specific city schools. Some schools showed dramatic improvements, such as Cardozo High School in Northwest where scores increased by as much as two years in some subjects, while scores at other schools, such as Anacostia High School in Southeast, fell by as much as a year.

The schools generally considered the city's best maintained their standings. For instance, students at Murch Elementary, Kelly Miller Junior High and Banneker Academic High schools all scored two to almost four years above national norms. Schools scoring the lowest were Spingarn and Anacostia High schools.

McKenzie hesitated to publicly criticize individual schools, but said that the uneven pattern of academic performance among city schools was due to below-average leadership and weak organization at some schools and outstanding leadership at others.

She said a special project was launched recently to identify exemplary principals and teachers at the best schools in the city to serve as role models.

A mentor-teacher program also was started last year to enable teachers just graduated from college to learn techniques from some of the best teachers in the system.

School officials have attributed the continued below-average performance of junior and senior high students to the fact that older students began attending school at a time when students were promoted to higher grades without real regard for their understanding of basic skills. Younger pupils have benefited from enrichment programs.