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The Florida Department of Education released reams of data Monday on how well teachers did in increasing student learning—but both the agency and the state’s largest teachers union cautioned parents against reading too much into the numbers.

The dizzying array of spreadsheets made public under court order included results for schools, districts and individual teachers. As a result, some of the documents were dauntingly lengthy—in one case, a spreadsheet including results for the state’s math teachers contains 133,580 rows of results.

Compounding the difficulty parents might have sifting through the data: the complicated mathematical formula that the department uses to calculate scores under the “value added” model, which spits out a number for each teacher.

A positive number means that student achievement grew more than would be expected when certain social and demographic factors are taken into account; a negative number means that student learning didn’t do as well as it would be expected to do.

Those numbers are later combined with other elements, such as a principal’s observation of a teacher, to come up with an evaluation for each teacher.

The Department of Education and the Florida Education Association fought to keep the data from being released, but lost a court battle to The Florida Times-Union in November.

“In addition, because these data are intended to be used in conjunction with other information about classroom practice to form a complete evaluation, looking at this information in isolation can lead to misunderstandings about an individual teacher’s overall performance,” Kathy Hebda, chief of staff at the Department of Education, told reporters in a conference call Monday.

The “value added” model was created as part of a performance-pay bill that passed the Legislature in 2011. The FEA, which waged a ferocious fight against the performance-pay measure, maintains that the formula is so flawed and complicated that it is essentially useless.

“Assessments of teachers, like assessments of students, must be valid, transparent and multi-faceted,” FEA President Andy Ford said in a statement Monday. “These VAM calculations are none of these. … They cannot measure the value of an individual teacher”

In November, a unanimous three-judge panel of the 1st District Court of Appeal sided with the Times-Union and overturned a Leon County circuit court ruling sealing the records.

The appeals court rejected arguments by the state and a teachers union that the documents should be exempt under a part of state law that shields teacher evaluations from public view until the end of the following school year.

“Had the Legislature wanted any matter material to a teacher’s evaluation to be exempt from disclosure, the Legislature would have exempted personnel files as a whole,” Judge William Van Nortwick wrote for the court. “To the contrary, personnel files of public school teachers are generally subject to disclosure.”