Chicago parents can expect to have a harder time comparing schools their children attend and their tax dollars fund this year, as the dedicated website the Illinois State Board of Education proudly touts won’t be ready for several more days.

ISBE will meet its statutory requirement to publish its trove of public school data by 12:01 a.m. Oct. 31, agency spokeswoman Jackie Matthews said Monday. Multi-page PDFs for individual schools are downloadable via ISBE.net. But massive errors in data for public schools in Chicago rendered preliminary data, typically made available to reporters a week in advance, virtually useless. And an unusually late final check of the data means it won’t be accessible until Friday on ISBE’s Illinoisreportcard.com website, where several years worth of trends can be viewed and compared with other schools and districts, ISBE said.

The Daily Herald, however, already has compiled its own School Checker database, which is available here.

State superintendent Tony Smith said Monday that finalizing the numbers was complicated by this year’s change to the SAT test for high school juniors from the ACT, given previously, as well as the breakout of the hundreds of data points by individual charter campus instead of lumping them by network.

Such changes “placed increased stressors on our report card processes this year,” during data verification, Matthews said.

CPS spokesman Michael Passman, who refused multiple requests to make any schools officials available for an interview typically granted for state report cards, blamed the state.

“Since receiving a preview of the report card data on Oct. 19, we have been in communication with ISBE to provide supplemental data and attempt to understand how our internal calculations differ from their findings,” he wrote in an email, saying, ISBE didn’t send CPS district-level data for verification until Oct. 19 and school-level data landed on Oct. 25, due back the next day.

The Noble Network of Charter Schools were missing basic figures, such as entire grade levels and graduation data for its oldest campus. Freshman on-track rates were listed as 0, and nothing at all had been reported for the college enrollment rates Noble prides itself on, spokesman Cody Rogers said.

“I don’t know how legitimately you can report on this stuff if the quality is bad,” Rogers said, adding that Noble officials heard similar complaints from other Chicago charters.

As much as Mayor Rahm Emanuel and his schools leaders have been touting CPS’ academic progress in recent months, CPS brass challenged the state on such basic measures as graduation rates that until late Monday were too high to be true.

CPS has already published many school quality measures and student demographics on its own website. What the state adds in a single place are scores from state-mandated tests — currently the PARCC test for grade schoolers and the SAT for high school juniors — as well as additional details like teacher absence and class size that are useful in piecing together a picture of a public school.

ISBE also keeps track of a growing number of charter schools that are under the control of the Illinois State Charter School Commission instead of a traditional district. Chicago now has six such schools within city limits, now educating about 2,200 children, three of which CPS tried to close for poor academic performance.