In experimental designs with nested structures entire groups (such as schools) are often assigned to treatment conditions. Key aspects of the design in these cluster randomized experiments include knowledge of the intraclass correlation structure and the sample sizes necessary to achieve...

Previous findings from experimental and non-experimental studies have demonstrated that teachers differ in their effectiveness. In addition, evidence from non-experimental studies has indicated that teacher effects can last up to five years. This study used high-quality data from a four-year...

Evidence from Project STAR has suggested that on average small classes increase student achievement. However, thus far researchers have focused on computing mean differences in student achievement between smaller and larger classes. In this study I focus on the distribution of the small class...

Previous findings from experimental and non-experimental studies have demonstrated that teachers differ in their effectiveness. In addition, evidence from non-experimental studies has indicated that teacher effects can last up to five years. This study used high-quality data from a four-year...