There's a big change in the works for Colorado teachers. Under a new state law, teachers will have to start proving every year they are "effective" or their jobs could be at stake. What counts as "effective" though? Well, it's complicated, and the state still has to figure how to measure teachers' work. Colorado Public Radio is looking at this question in our series "What Makes a Great Teacher" and we continue that today. We're going to talk about whether you can teach someone how to be a good teacher, or even a great one. We hear from two people whose jobs are to help teachers get better. Brenda Kaylor is a consultant who leads teacher effectiveness workshops in school districts around the country. And Beth Low is one of Jefferson County Public Schools' “instructional coaches”. She's a former science teacher and she coaches teachers at Arvada West High School. She says there are many ways to help a teacher improve.