A Pilot Study of the Impact of Double-Dose Robust Vocabulary Instruction on Children's Vocabulary Growth.

ABSTRACTDouble-dose instruction, in which instructional lessons are supplemented to provide additional instructional time, is a mechanism used in some schools for boosting outcomes in certain academic areas. The purpose of this study was to examine the effects of double-dose vocabulary instruction, relative to single-dose and business-as-usual control instruction, for pre-kindergarteners through third-graders in a quasi-experimental pilot study; the vocabulary instruction was embedded in a more broadly focused language-comprehension intervention. Pretest, posttest, and measures of targeted vocabulary were collected over a 21-week period of implementation to investigate children's vocabulary development during the intervention. In general, single- and double-dose instruction resulted in equivalent effects on children's learning of targeted vocabulary, although effect-size estimates were always larger for the double-doses condition relative to single dose. Both were superior to the business-as-usual instruc...