The state Legislature, the governor and the Department of Education -- everyone involved in the planned Keystone Exams, in fact -- deserve an F for implementing the new standardized tests for Pennsylvania high schoolers.

The Education Department recently agreed to Gov. Tom Corbett's budget proposal, which calls for watering down the exams and delaying their start by two years.

As originally proposed three years ago, the Keystone Exams were a series of end-of-course tests for high schoolers to show they're competent in a subject, with the results counting toward their final grades in the courses.

It was supposed to replace the Pennsylvania System of School Assessment exams for 11th-graders, who would have had to pass seven of 10 tests in order to graduate.

In theory, it was a good idea.

The PSSAs now require high school juniors to recall about three years worth of information, and the tests were criticized because the students didn't have an incentive to take them seriously. The results didn't affect their grades -- much less whether they received a diploma.

The Keystone Exams would have given a more accurate picture of students' knowledge. The tests were to be administered as soon as they completed the courses -- rather than possibly years later -- and the students would have given it their best effort knowing their grades were on the line.

But when it came to execution, the plan was bungled badly.

After spending $24.3 million to develop the exams, the Legislature last year cut off funding for the Keystones, even as some school districts were administering them through a pilot program.

In his 2012-13 budget proposal, Corbett requested $15 million be reinstated for the tests, but he proposed delaying them and scaling them back.

The Keystones were supposed to be in place for the class of 2015, but the Department of Education now has agreed to push them back to the class of 2017 -- this fall's eight-graders.

And rather than passing seven of 10 Keystone Exams, the students only will have to take three tests -- in Algebra I, biology and literature. A composition exam will be added for the class of 2019, and a civics and government test for the class of 2020 -- but that's still only half as many tests as were initially suggested.

Even more annoying: Although the class of 2017 will still have to pass the exams to graduate, their scores won't count toward their final course grade -- stripping much of the accountability from the original plan.

The constant tinkering and delays also are causing problems with Pennsylvania's ability to meet federal No Child Left Behind standards.

Even though the Keystone Exams have been delayed, the state is going ahead and eliminating next year's 11-grade PSSAs -- the standard by which the federal government ensures students are making adequate yearly progress.

Without the PSSAs or a substitute, it's unclear how Pennsylvania high schools will comply with No Child Left Behind next year.

State officials are reportedly talking to the U.S. Department of Education about the issue -- although it seems that should have been settled before any decisions were made.

It's a strange move, but not so unusual, we suppose, for the folks behind Pennsylvania's Keystone Exams.