For the first time since introducing school progress reports in 2007, the Department of Education has reduced the weight of state test scores in determining middle schools’ scores on their state test scores.

The change is slight, allocating just 5 percent of the calculation toward the grades schools hand out, but it reflects a significant shift within the Department of Education. After years of saying that the state’s current tests are not the ideal measure of students’ abilities, the department is — to a limited extent — putting its metrics where its mouth is.

Until now, 85 percent of elementary and middle schools’ scores have come from crunching the scores in different ways. But on the 2011-2012 progress reports, which are coming out today, that proportion has dropped slightly for middle schools, to 80 percent. The difference will be made up by schools’ course passage rates in the core subjects of English, math, science, and social studies.

The change, which the department promised a year ago, makes year-to-year progress report score comparisons hard to make yet is unlikely to dramatically alter schools’ scores on its own. Still, it signals that the city is projecting onto middle schools growing concerns about the mismatch between how city students perform on some high-stakes accountability metrics and how well prepared they are to take on more challenging work.

The mismatch has fueled a new aim for “college readiness” rather than simply graduation eligibility at the high school level, but it is just starting to have an influence in the primary grades. This year, for the first time, middle schools will get credit for the proportion of students who pass their core classes, considered an important precursor for high school success.

Recognizing that the accountability change introduces a new incentive for schools to hand out, or even mandate, potentially unearned passing grades, the department says it is on the lookout for schools where many students pass their classes but cannot pass the state’s math and reading tests.

“If we find cases where course passing rates are far out of alignment with both state exam performance and state exam progress we may redistribute points from the course metrics to the exam metrics for those schools,” reads a document that principals received last month to help them interpret their schools’ progress reports, which they received in advance of today’s public release.

Plus, the document warns, “The DOE is increasing oversight of schools’ grading polices. Schools may be asked to provide documentation of grading policies for review to justify student course performance results.”

The city has also awarded extra credit to middle schools where many students have passed a high-school level course or exam before leaving eighth-grade. One goal of the city’s 2007 middle school reforms, which quickly lost steam but got new attention after Chancellor Dennis Walcott announced a middle school overhaul last year, was to expand high school-level coursework in middle schools.

Next year, middle schools will also be scored on how their graduates perform in ninth grade, when they are confronted with higher expectations and different grading standards. For now, that data will appear on the progress report, offering a view into middle schools that might have promoted students who were not ready for high school, but won’t be figured into schools’ final scores.

In an education department that’s driven by data, what gets measured is a clear expression of values, and other changes to the progress report signal that the department is placing a new emphasis on the success of individual students rather than simply on schools as organizational units.

In one example, schools have long been eligible for “extra credit” based on how quickly they boost the test-scores of various groups of high-needs students. But in the past, schools have been ranked according to how much extra credit they earned, and only the top 40 percent received any progress report score boost. This year, every school with students who meet the standard for extra credit will earn some, and schools with more high-needs students will get more extra credit.

The city is also giving more weight to third-grade test scores, with a large portion of elementary schools’ scores going to an “early grade progress” metric that weights scores according to students’ demographics. And schools will also be able to earn extra credit for English language learners who advance quickly. Until now, extra credit has gone to schools that move low-performing students and black and Hispanic students forward, but there has not been a separate category for ELLs.

And in another non-graded change, this year’s progress reports will show how students performed in each grade, although the total score will still be based on the aggregated scores. “We have received feedback that reporting this kind of additional, concrete information about student achievement in the Progress Report would be useful to school staff and families,” the city’s guidance to principals reads.

None of the elementary and middle school changes alone is as as dramatic as the one that will hit high school progress reports when they come out later this month. Students’ college-readiness rate will count for 10 percent on this year’s high school reports, inducing potentially significant score declines for schools that have successfully gotten students to graduation but not prepared them with even the most basic college-level skills.

Concerns about the graduation-skills mismatch were one reason that the department last year introduced new policies to guard against soft grading on high school Regents exams and limit students’ ability to make up missed credits without retaking failed courses.

The city uses the progress reports as part of its determination of which schools to close and which principals to reward.

UPDATE: This article originally stated that elementary schools, which do not have core courses, were subject to the change in the way progress report scores are calculated.