Impact of the Developing Mathematical Ideas Professional Development Program on Grade 4 Students' and Teachers' Understanding of Fractions

The purpose of this study was to assess the impact of the Developing Mathematical Ideas (DMI) professional development program on grade 4 teachers' in-depth knowledge of fractions as well as their students' understanding and proficiency with fractions. The study was conducted during the 2014/15 school year. A total of 84 schools from eight school districts in three states (Florida, Georgia, and South Carolina) agreed to participate. Participants included 264 grade 4 teachers and their 4,204 students. The study utilized the "gold standard" methodology involving random assignment of schools to either DMI or the control condition. Teachers in the DMI condition participated in 24 hours of professional development on fractions during fall 2014. They attended eight 3-hour sessions conducted over four days (two 3-hour sessions per day; one day per month). DMI did not demonstrate any impact on student knowledge of fractions. Students of DMI teachers performed at almost the same level as those taught by control teachers; the difference was not statistically significant. The impact of the DMI on teachers' knowledge of fractions was inconclusive. DMI teachers performed slightly better than teachers who did not participate in DMI, but the result was not statistically significant. It was, however, close to the threshold of statistical significance (p = .051).