Cambridge school officials say they are looking into how boycotters skewed their test results.

Last year, more than 90 percent of tenth graders took the MCAS tests statewide. But in Cambridge, about 30 percent of sophomores--around 150 students--were absent from the test.

In their statistics, the state Department of Education gives a student who misses the test a score of 200, the lowest possible score. This practice distorts district-wide results in Cambridge, said Barbara Black, who analyzes test scores for the district.

According to Black's preliminary analysis, treating the boycotters differently could yield dramatically different results.

Among students who actually took the English test, she said, the failure rate was 53 percent--not 67 percent, as the state reported. On the math test, the rate was 64 percent--not 75 percent.

Discounting the students who did not take the test does not give a truly accurate picture of how tenth-graders performed on the MCAS tests, Black said. She said she has no way of knowing how the boycotters would have scored had they actually taken the test.

But Black said using the valid results was "standard operating procedure."

The King Open School traditionally has high MCAS scores. But only 18 of the school's 32 fourth-graders took MCAS last spring, which directly affected test scores. This year the King Open's numbers are down significantly, Groves said.

Not only school district results are skewed. State education officials have urged districts to use individual students' MCAS scores to identify their strengths and weaknesses, Groves said, which becomes impossible when there are no results to analyze.

"It's been a little hard to use it that way with this many kids not taking it," he said.

Statewide Summary

Driscoll presented the district-by-district results in an East Boston elementary school yesterday, flanked by Boston Mayor Thomas M. Menino and Thomas Payzant, superintendent of the Boston Public Schools.

Driscoll acknowledged that the gap between urban and suburban districts remained wide, but he said districts needed to keep working towards higher standards.

"We need to set a standard. We can't move the standard," he said.

"Boston clearly has gotten their act together. I think Boston is the exception," he added.

District with low scores "did not have a good plan, did not have supports in place," Driscoll said.