Background: Cluster-randomized experiments that assign intact groups such as schools or school districts to treatment conditions are increasingly common in educational research. Such experiments are inherently multilevel designs whose sensitivity (statistical power and precision of estimates) depends on the variance decomposition across levels.…

Boys identified as learning-disabled gifted or twice exceptional, at two different grade levels (5th or 6th grades, and 11th or 12th grades), were asked to read a history text with unknown vocabulary words, internal inconsistencies, and prior knowledge violations inserted to make immediate comprehension difficult. The students were asked to read…

In 10 schools, reading levels of 11th-grade agriculture students were measured, and teachers estimated the readability of agricultural magazine articles. Teachers who ask students to read aloud and who provide reading assistance estimated reading level and readability more accurately, although neither group was very accurate. (SK)