Most of us aren't airline pilots (apologies to many who are, and who live here thanks to DFW Airport). So most of us never look out the front window as our big jet heads through a cloud.Most of us look out the side windows, see nothing but cloud and hope somebody up there knows for sure what's on the other side of it.We're seeing a lot of cloud these days when we look at the future of the accountability system for Texas public schools.We don't know whether the sun is shining on the other side.We know the system that is coming for our neighborhood schools and school districts will be different.Education Commissioner Michael Williams last week said what he believes it will look like. But he also acknowledged that the Legislature is considering bills that would address the accountability system from different angles, and he said any changes approved by lawmakers before they adjourn May 27 will have to be folded in.He said he's moving ahead with plans to give schools A, B, C, D, or F grades beginning in 2014. He likes that idea, but not everyone in the Legislature does.Switching from the exemplary, recognized, acceptable or not acceptable ratings in place for several years was one of several changes in a major education bill passed by the House, HB5, but A-F grades were stripped out by the Senate.The system laid out by Williams is different in about every way imaginable by people who aren't education experts.It will use a "performance index framework" rather than what many people see as an over-reliance on standardized test scores today.Districts and school performance will be given pass/fail ratings in four categories:Student achievement. This is much like today's system, based on test performance across all subjects.The big difference is that the ratings will focus on the performance of all students in the school or district, without looking at that of the racial, ethnic and economic sub-groups that can lower ratings in the current system.The index for this year's ratings is that schools will be given a passing grade if their test scores are at least 50 percent of the maximum.Student progress. This category focuses on performance improvement, broken down by racial and ethnic (but not economic) sub-groups as well as English language learners and special education students.In this category, passing schools will be those that show better progress than the lowest 5 percent of schools in the state. That means about 383 schools out of more than 7,600 in Texas will fail on this measure, according to Texas Education Agency documents.Closing performance gaps. This category focuses on bringing economically disadvantaged students and the lowest-performing racial and ethnic groups up to what is considered advanced academic achievement.Passing schools will be those whose low-performing students reach at least 55 percent of the advanced performance goal.Postsecondary readiness (applies only to grades 9-12). This is dropout rate measure in reverse. TEA says passing schools will be those in which 75 percent of the students "receive a high school diploma that provides them with the foundation necessary for success in college, the workforce, job training programs or the military."Many people see today's system as too "all or nothing." Williams' plan would enable school districts to point to one or more of the measures in which they rate well rather than live under a single good or bad label.That is, they can once they understand how the system works.Suzanne Marchman, a spokeswoman for the Texas Association of School Administrators, says they're not there yet."This new system is even more complex than the previous one," she wrote in an email to the Star-Telegram Editorial Board. "It will be a challenge to explain to parents when we are struggling to understand the nuances of this system ourselves."Sort of like that cloud outside the window of the airliner.