Co-Principal Investigator: Joseph R. Jenkins (University of Washington)

Purpose: The ability to understand written text is highly dependent on knowing the meaning of individual words. The well-established positive relation between vocabulary and comprehension suggests that high quality vocabulary instruction should benefit comprehension. In this efficacy study, the research team will test the efficacy of rich vocabulary (RVOC) instruction compared to typical (i.e., business-as-usual) vocabulary instruction for students in fourth and fifth grade. RVOC instruction is intensive, provides frequent and varied encounters with targeted vocabulary words, and has been found to improve reading comprehension in prior quasi-experimental research conducted with small samples. The current study will attempt to replicate this prior research using more methodological rigor, including the use of random assignment and a larger and more diverse sample.

Project Activities: The efficacy of RVOC will be tested using a multi-cohort randomized design. In each of three years, 20 fourth- and fifth-grade teachers (and their students) will be recruited and randomly assigned to treatment (implementation of RVOC) or control (teachers' regular, business-as-usual classroom vocabulary instruction) conditions.

Products: The expected products of this study include published reports on the effects of rich vocabulary (RVOC) instruction on the vocabulary knowledge and reading comprehension of students in fourth and fifth grade. Products will also include findings on whether students' baseline skills in vocabulary and comprehension, or the amount of instructional time on vocabulary and comprehension activities, moderate any treatment effects.

Structured Abstract

Setting: The evaluation will take place in elementary schools in a large urban area in Washington state.

Population: The study participants will be 60 fourth- and fifth-grade teachers and their students.

Intervention: RVOC instruction occurs daily during teachers' regular language arts block for 30 minutes per day for 14 weeks. RVOC instruction includes multiple and varied encounters with words and opportunities to practice words through defining tasks, sentence generation tasks, classification tasks, oral and written production tasks, games under timed conditions, and tasks that stress the semantic or affective relationships between the target words and previously acquired vocabulary. The treatment instruction will be coordinated with the reading of two grade-level novels, which will be provided to both the treatment and control classrooms.

Research Design and Methods: In this efficacy study, teachers will be randomly assigned to the treatment or the control group. Three cohorts of 20 fourth- and fifth-grade teachers will participate each year. All students from participating classrooms with parental consent will be assessed prior to the implementation of the intervention and following the completion of the 14-week intervention period. All teachers will be observed during their language arts instruction block at the beginning, middle, and end of this 14-week period to assess fidelity in the treatment condition and quantify vocabulary and comprehension instruction in the control condition. All students will be assessed on measures of vocabulary and comprehension.

Control Condition: Teachers who are assigned to the control group will implement their typical, business-as-usual instruction during the language arts block.

Key Measures: Vocabulary and comprehension will be assessed using the Iowa Test of Basic Skills and experimenter-designed tasks using the taught words. Instructional content and student grouping arrangements (e.g., vocabulary instruction in small groups versus individualized word study) in both the treatment and control classrooms will be measured with the Instructional Content Emphasis-Revised (ICE-R).

Data Analytic Strategy: Multilevel modeling will be used to test direct and conditional cross-level treatment effects of classroom RVOC instruction on student outcomes.

Products and Publications

Journal article, monograph, or newsletter

Vadasy, P. F., Sanders, E. A., and Logan Herrera, B. (2015). Efficacy of Rich Vocabulary Instruction in Fourth- and Fifth-Grade Classrooms. Journal of Research on Educational Effectiveness, 8(3): 325–365.