It sounded bad last week when the feds labeled Oregon “at risk” of failure on teacher evaluations. But, in fact, Oregon is smart to take more time to design a better system.

The core issue is the use of student test scores in teacher evaluations. Many teachers and their unions are resisting pressure to judge teachers that way, saying it doesn’t accurately reflect good teaching and can pervert the process in ways that hurt students.

The U.S. Department of Education, however, demands that states implement such systems if they want waivers from No Child Left Behind’s requirements.

When Oregon got its conditional NCLB waiver last year, it promised to come up with a teacher evaluation system that incorporates student scores by this spring. Now it says it needs another year, prompting the “at risk” label and a requirement to make monthly reports to the feds on its progress between now and a new deadline of May 1 next year.

If Oregon misses that deadline and loses its waiver, the consequences would be draconian. About 600 schools statewide would be added to a needs-improvement list and required to offer students transfers and transportation to schools not on the list. No one expects that to happen, though. Oregon is well on its way to designing a system, but wants a year to test and refine it.

While we firmly believe student test scores must be part of teacher evaluations, there’s no doubt it’s a tricky process. Methods are needed to correct for factors beyond the teachers’ control, such as the background and capacity of students in the class. The results of ongoing research projects should be considered.

And there’s a wild card on the horizon in new Common Core standardized tests, due for implementation in the 2014-15 school year. Early results suggest scores will fall dramatically when the new, more-demanding tests are administered. That’s fine, and definitely worth it to bring schools up to more rigorous standards, but it must be factored into decisions on teacher evaluations.

Given the difficulty of the assignment and the controversy surrounding the subject, an extra year is a wise investment.