It is vitally important to teach key words that children will need to learn content and comprehend texts. Given that students' success in school and beyond depends in a large degree upon their ability to read with understanding, there is an urgency to providing instruction that gives students with the skills necessary for lifelong vocabulary development. Therefore, vocabulary instruction should emphasize useful words that promote independent understanding of the words. The purpose of this quantitative experimental study with a pretest-posttest comparison design was to explore the degree to which the implementation of explicit systematic vocabulary instruction using Tier 2 words impacted the reading comprehension of first grade at-risk readers.

Participants included first grade students who were identified "at risk" through the Developmental Reading Assessment 2. These students were pulled out for an additional 20 minutes a day for reading interventions using a direct approach to vocabulary instruction. Students who were not given an intervention had vocabulary instruction in the classroom. The process of teaching new terms, for all students, was broken into five steps; the first 3 steps focused on introducing new words and the final two steps suggest ways to review the words.

Experimental descriptive quantitative data were used for analysis. The results of the Friedman test, Wilcoxon post hoc analyses, and the descriptive data indicated that students in both the intervention group as well as the students not pulled had made improvement on the DRA2.