Most American students are familiar with computers, but only a few can handle the equipment skillfully or use various programs to solve problems, the National Assessment of Educational Progress said Tuesday.

The NAEP's 1986 assessment of computer competence, described as the first in that field for the 19-year-old educational review, found more than two-thirds of a nationally representative sample of 24,000 students in the third, seventh and 11th grades able to identify a keyboard, disk drive and printer.At all three grade levels, however, students averaged less than 50 percent correct when examined for knowledge of computer technology, understanding of computer applications and familiarity with computer programming.

"Students have a broad awareness and a basic understanding of computers, but their grasp of the concepts involved, or so-called higher order skills such as solving problems by using a computer program, has not yet been developed," explained Archie Lapointe, executive director of the NAEP.

Lapointe said the results parallel problems students have in reasoning and applying information in other subject areas. But the study stressed the importance of computer competence, warning: "America's prominence in the world economy rests to a large extent upon its technological competitiveness. . . . No longer is it sufficient to be competent in the three Rs."

Interpreting the results, Lapointe noted American educators "disagree over what should be taught about computers in schools." He pointed out further that many computer coordinators have minimal training in computer studies and rate themselves as mediocre in their ability to use the equipment.

Based on responses of 837 computer studies coordinators from about half the sampled schools, the study found 32 percent of the third-grade coordinators, 23 percent of the seventh-grade coordinators and 10 percent of the 11th-grade coordinators did not feel adequately prepared to teach computer science.

Other findings included:

About 75 percent of third graders, 89 percent of seventh graders and 87 percent of 11th graders had used a computer, but there was a decline in computer instruction, especially between the seventh and 11th grades.

High percentages of seventh- and 11th-grade students, up to 87.5 percent, never had used a computer to practice math, reading and other skills from traditional subjects, but as many as 80 percent had used one to play games.