WASHINGTON -- Are you a parent who thinks it's hard for schools to get bad teachers out of the classroom?

According to a new survey, there are teachers who would agree with you.

More than half of teachers polled believe it's too difficult to weed out ineffective teachers who have tenure. Nearly half said they personally know such a teacher.

The findings are in a survey released by the Education Sector, a nonpartisan think tank.

Tenure provides teachers with job security and generally is awarded a few years after educators enter the profession. It's supposed to ensure that teachers can't be fired at the whim of a principal or angry parent.

But it also can make it extremely difficult to dismiss a teacher who is doing a bad job.

According to the survey, a majority of teachers think the evaluation process for new teachers should be strengthened, so that weak teachers don't become entrenched.