Teacher Talk and Literacy Gains in Chilean Elementary Students: Teacher Participation, Lexical Diversity, and Instructional Non-present Talk.

• This study simultaneously tackles conceptual, interactive, and linguistic dimension of talk. • A positive quadratic effect of teachers' lexical diversity on early literacy gains was found. • Lower student participation in Instructional Non-Present Talk displayed lower literacy gains. • High teacher participation with teachers' high lexical diversity impacted negatively in literacy. Although the relation between child-caregiver non-present talk and children's language and literacy development has been extensively studied, scarce research has examined the contributions of teacher talk's conceptual, interactive, and linguistic dimensions to early literacy. Using fine-grained linguistic analysis, lessons from 16 Chilean classrooms from Pre-K to 2nd grade were coded for: conceptual (non-instructional, instructional present, instructional non-present), interactive (teacher-student talk ratio), linguistic (syntactic complexity, lexical diversity). Students were administered baseline and end-of-year literacy assessments (n=343). Controlling for school, classroom, and individual-level factors, HLM analyses revealed a positive quadratic effect of teachers' lexical diversity on early literacy gains and a negative effect of teacher-student talk ratio, such that classrooms with greater teacher participation in instructional non-present talk tended to display lower literacy gains. A significant interaction revealed that at greater levels of teacher participation, teachers' higher lexical diversity negatively impacted literacy gains. [ABSTRACT FROM AUTHOR]