he purpose of this study was to determine the effects of one approach to vocabulary instruction on the reading and writing vocabulary of fourth grade students in an individualized reading program. The vocabulary instructional approach used student-selected vocabulary words as well as instruction in vocabulary strategies such as context clues, structural analysis, and definition strategies. The twelve week study exposed one fourth grade classroom to vocabulary instruction in a Reading Workshop setting. Major components of the program were mini-lessons, which often involved vocabulary strategies, the silent reading of self-selected books, one-on-one researcher/student interactions, and the self-selection of vocabulary words. The research design is descriptive in nature and used both qualitative and quantitative research methods. Qualitative data included student interviews, teacher interviews, student writing samples, and field note observations. Quantitative data included vocabulary test scores from two groups of students, Group A and Group B. Group A participated in the self-selected vocabulary approach and received vocabulary instruction from the researcher acting as participant observer. Group B received some vocabulary instruction from their classroom teacher, but did not participate in the same program. The test was constructed weekly from a class (Group A) generated list of ten words. Results from vocabulary tests …