We've long been arguing that districts could tap retired teachers to ease the transition of new teachers into the classroom. We recently found a great example of a district doing just that, Aurora Public Schools in Colorado.

Aurora designed a program to engage retired teachers as mentors, and it appears to have had strong effects where it matters most: on the math and reading achievement of the students assigned to these well-mentored new teachers. After the first year, those classrooms reported gains equivalent to one month of additional learning in math and about the same in reading after two years. Although the impact wasn't found to be quite as large as that of the New Teacher Center's year-long, mentor-based induction program, Aurora's program targeted a broader swath of teachers (all those new to the district, even if they had several years of teaching experience elsewhere). Aurora's teachers may not have had the same professional learning needs as the true novice teachers included in a recent study of the New Teacher Center approach.

Aurora layered this new program on top of its "business as usual" support, in which new teachers were always paired with a "buddy" who provides at least 15 hours of support and a mentor who provides at least 30 hours of guidance and opportunities to collaborate over the course of each year.

The program didn't have much of an impact on the new teachers' evaluations, but that may speak to a weakness in the evaluation process more than to a failing of the program, as the program participants were demonstrably more effective in advancing student learning. While the program was not found to improve retention rates overall, the study revealed a strong relationship between the total hours spent with a mentor and the likelihood that a teacher would stay in the district. Each additional hour of mentoring increased the odds a teacher would return the following year by 12 percent.

Implementation costs ran approximately $171 per student—a bargain according to the researchers who also estimated that the growth in achievement was likely to translate into an additional $2,760 in lifetime earnings for the students taught by teachers in the program.