| The purpose of this study was (a) to determine if 4th grade students could learn academic vocabulary words or tier II general words using a vocabulary intervention program referred to as the lexicon enhancement program (LeEP), and b) to determine if the category of vocabulary words (tier II general vs. academic) impacts the number of vocabulary words learned, general vocabulary abilities, and reading comprehension. A total of 111 fourth graders participated in this study. Six classrooms were randomly assigned as either the academic group, tier II group, or control group. Pre- and posttest scores of the Zero-One-Two (ZOT; Robinson, 2013) were gathered to assess vocabulary knowledge, and pre- and posttest scores of the Measures of Academic Progress (MAP; Wang, McCall, Jiao, & Harris, 2013), a standardized, computerized test, were gathered to assess reading comprehension and general vocabulary abilities of all participants. Results revealed that intervention groups showed gains in vocabulary knowledge over the course of the intervention program when compared to the control group. Furthermore, posttest scores of the ZOT total score and ZOT words known were significantly higher for the academic group than the control group, indicating that teaching academic vocabulary words had a greater impact on the number of ZOT words that were learned than teaching tier II vocabulary words. Statistically significant gains were not discovered in general vocabulary abilities or reading comprehension for the interventions groups when compared to the control group suggesting that the LeEP did not generalize to general reading comprehension and vocabulary skills. |
