The document summarizes research testing the effectiveness of using semantic mapping to teach vocabulary in various high school classes. Tests were given before and after implementing semantic mapping to measure changes in students' vocabulary scores and comfort with vocabulary. The results showed that semantic mapping significantly improved vocabulary scores in English and government classes, and increased students' reported use and understanding of vocabulary words. However, vocabulary was still rarely observed being used independently in class discussions. The study suggests semantic mapping is an effective strategy, but implementation and data collection could be improved in future research.