The Johns Hopkins Language and Literacy Project (JHLLP) is a comprehensive professional development program and curriculum designed to train Head Start teachers in strategies that promote language and literacy development in young children. The project includes intensive, ongoing teacher coaching, 25 theme-based modules, and books and literacy activities related to themes. The training focuses on five components: oral language development, book reading, alphabet knowledge, phonological awareness and writing. The goal of the program is to promote vocabulary and language skills in Head Start children. As a part of the CORS Head Start University Partnership grant, the JHLLP has been implemented and evaluated in 10 classrooms in Baltimore City Head Start in Maryland. The data from Year 1 and 2 show that intervention classrooms perform significantly better than control classrooms on measures of expressive and receptive language. The findings also indicate children who are in classrooms where teachers are implementing the language and literacy strategies perform better on the assessments compared to children who are in classrooms where teachers are not implementing the strategies. Measures of classroom quality indicate that the quality of the language and literacy usage changes due to the JHLLP intervention. Two assessments that support the program have been developed as part of the CORS grant. One assessment is consistent with the format of the Creative Curriculum assessment yet has specific items that assess the five language and literacy component of the JHLLP model. The assessment includes both a child and teacher component. The teacher observes each child and determines whether the child is demonstrating certain target behaviors such as the child's ability to acquire new words, the child's knowledge of print, and the child's ability to express his/her ideas in words. The teacher also assesses their own practices that support the language and literacy development of the children. The assessment is designed to help teacher modify the curriculum to meet the needs of the children. A second assessment was developed to measure the vocabulary development of children. Throughout the curriculum there are target vocabulary words that are taught through the books, props, and center activities. The vocabulary assessment is designed to determine whether children have acquired both expressive and receptive understanding of the target words. Children are shown a picture with the objects that represent the vocabulary and, through a series of prompts, are asked to identify the objects. This assessment provides the teacher with an individualized summary of the child's word knowledge. Piloting of this measure is currently taking place. In sum, the JHLLP has shown to have a positive impact on Head Start children's language and literacy development. Training teachers to learn to talk and interact with their children in order to facilitate the development of children's language and vocabulary skills requires ongoing support and feedback from trained staff.