Correction: In examining prior cohort data, in turns out that what ISBE and the IIRC call cohort data is not what I describe it as below. In fact, the IIRC “cohort” just compares the scores of all 3rd graders in year t to all 4th graders in year t+1. The trouble with doing this is that not all 3rd graders in year t stay in the same school for year t+1 and some new students arrive from other schools. Now CPS did distinguish in this more accurate way as part of its value-added scores; I had assumed they drew on the same data that went into the cohort study. I was wrong. CPS assembled this dataset itself (CPS has not issued value-added scores for 2013 ISATs, probably because they are moving over to NWEA MAP to measure teacher and principal performance). Nevertheless, I do not see why the IIRC site cannot be updated publicly when the data has been there since July. Now parents have to download a bulky Excel file to find out how their school performed.
The 2013 ISAT scores for Illinois schools have been out since July 2013. But the more helpful data, how cohorts of students have performed, has only been available to school officials. The public has no access to it. And the Illinois State Board of Education refuses to release it to the public until the last moment possible under state law, 31 Oct. That date is the deadline by which ISBE must release the data. But the board members apparently don’t know what a deadline is. They have the data, but they have chosen to deny it to the public until the last legal moment.
But, you might object, the 2013 ISAT results at the school and grade level were released in July. True, but that data is not all that useful.
Cohort data tells us, for example, how 3rd graders who took the test in 2012 did as 4th graders in 2013. [It should do this but the IIRC data does not.] The data we have available compares, for example, the set of 3rd graders in 2012 with the set of 3rd graders in 2013. That doesn’t tell us much about the school or the teachers; it tells us about the 3rd graders.