Last Friday, when the state released the most recent round of Massachusetts Comprehensive Assessment System (MCAS) test scores, there was some self-congratulation in the districts that improved. Cambridge was one of those districts—10th grade scores increased by 21 and 27 percent in the English and math sections, respectively. Superintendent of Schools Bobbie J. D’Alessandro hailed this accomplishment, writing in a press release that “We are very pleased with the overall MCAS results.”

At first glance, this looks like a considerable improvement, a positive omen for the future. But after scratching the surface, it seems that not much real progress has been made. The higher scores on year’s 10th grade MCAS test can be attributed to a variety of causes other than actual academic improvement.

Last year’s low scores were skewed due to the fact that a considerable number of high school students across the state boycotted the test. Because the test was only a trial for last year’s students, there were no penalties for missing the exam. As a result, about 30 percent of Cambridge sophomores stayed home last year, resulting in exceptionally low passage rates. This year, only a negligible number of 10th graders missed the test, and predictably the passage of passing students skyrocketed.

But it would be much more useful to look at the difference between the percentage of students who actually took the test and failed this year, as compared to last year.

Last year, 37 percent of Cambridge tenth graders who took the English section failed. This year, the failure rate dropped to 30 percent. And last year, 43 percent of Cambridge 10th graders who took the math portion failed; this year, that dropped to 36 percent. So there was about a 7 percent improvement rate for Cambridge’s sophomores in both sections—significant, surely, but far from the 20 percent gain that educators trumpeted.

Even those who did show up to take the exam last year likely took it less seriously than they would have if it had counted towards their graduation. Now that the test actually counts, it is unsurprising that scores rose.

It is also likely that some teachers, fearing that many of their pupils might otherwise fail, changed their curricula and activities to “teach to the test.” This almost certainly accounted for part of the rise in MCAS scores. But there is no way to know whether that accurately reflects knowledge gained, or whether other subjects and topics were sacrificed to make more time for MCAS practice.

Even after these considerable jumps in scores, only 53 percent of Cambridge’s sophomores passed both sections of the test. Those students will be able to graduate with a high school diploma. The other 47 percent have several more chances to retake the test. If they cannot pass, they will not graduate, though they may have completed all of their high school’s requirements.

It is safe to expect scores to improve incrementally over the next few years, but there will be no sensational jumps like this past year. Cambridge, and the state, must confront the shameful fact that, if these tests are maintained as a high school graduation requirement, thousands of otherwise-qualified students are going to be denied a diploma because they did not pass one standardized test.