Schools Chancellor Joel Klein announced Tuesday that starting in the fall of 2007, public schools will be graded on performance. Chancellor Klein says the new focus will be on progress. He says the current system doesn?t give enough credit to schools that show improvement. Under the new system students will take assessment tests every six weeks and their results will be made available immediately to principals, teachers and parents. There are also plans for on-site evaluations and classroom reviews. Based on the schools? environment, the six-week progress reports and the performance of students, all schools will receive letter grades ranging from A through F. Parents will be able to compare how the different schools stack up. Klein says this system will make Bronx and city schools the best in the country.