Well, joining us to explain the project is Los Angeles Times investigative reporter Jason Felch.

NPR: 'L.A. Times' Series Examines Teacher Ratings

Mr. JASON FELCH (Investigative Reporter, Los Angeles Times): Hi, Robert.

NPR: 'L.A. Times' Series Examines Teacher Ratings

Mr. FELCH: Well, the big takeaway from our series - and after, you know, spending a lot of time analyzing this data - is that individual teachers really matter.

NPR: 'L.A. Times' Series Examines Teacher Ratings

Mr. FELCH: Value-added is a somewhat complex statistical approach.

NPR: 'L.A. Times' Series Examines Teacher Ratings

Mr. FELCH: In California, under the Public Records Act, we were able to obtain this information from the school district itself, so the district's attorneys decided that this was actually public record information.

NPR: 'L.A. Times' Series Examines Teacher Ratings

Mr. FELCH: Thank you very much, Robert.

NPR: 'L.A. Times' Series Examines Teacher Ratings