Illiteracy is a social problem in America; approximately 40 million Americans are illiterate. Literacy is essential for success; however, millions of children in America are leaving school without the ability to function and contribute to a rapidly advancing society. Literacy is defined as the ability to use printed words and written information from a variety of sources effectively and efficiently to achieve goals, function in society, and develop knowledge and potential. Children who have difficulty reading often struggle in educational and academic settings, experience low self-esteem as a result of their difficulties, and are more likely to drop out of high school, further limiting their future opportunities. Research has identified some factors that contribute to literacy and language acquisition. Children from lower socioeconomic backgrounds are exposed to less literacy promotion in the home than middle- to upper-class children. Thus, this population is at greater risk for lower achievement scores and less academic success. Research also indicates that home environments, coupled with parental attitudes and beliefs, are critical influences on a child's achievement. Some literacy interventions have been implemented in order to decrease achievement gaps and to increase effective literacy-promoting behaviors. Project PRIMER (Producing Infant/ Mother Ethnic Readers) was a parent-focused community-based intervention designed to increase literacy and language acquisition by children in low-income, ethnically diverse families by teaching mothers dyadic reading techniques. Families were randomly assigned to receive 18, 3, or 0 instructional visits. Children who were assigned to the 18-instructional-visit program increased their achievement scores significantly more than children assigned to the 3- or 0- instructional-visit programs. The purpose of the present study was to examine potential mediators of the change in the children's achievement scores. Five mediation models were tested. All potential mediators were changes in the parental behaviors from the pre- to post-assessments. The mediators were: parental attitudes, the number of questions parents asked, parental teaching behaviors, the number of words spoken by the parent, and the number of words spoken by the child. Participants were 237 families who completed Project PRIMER's 18-instructional-visit program. Parents were also administered questionnaires to measure their attitudes and teaching behaviors. The parents and children were videotaped reading and playing together. The videotapes were coded to assess the changes in the number of questions and words spoken during read and play time. There was a negative correlation between children's pre-assessment achievement scores and changes in parental teaching behaviors, indicating that parents of low-achieving children increased their teaching behaviors more than parents of children who had higher achievement scores at the pre-assessment. However, parental teaching behaviors did not mediate the changes in children's achievement scores. The findings from the other mediation analyses indicated that none of the variables examined mediated the changes in children's achievement scores from pre- to post-intervention. This suggests that single-variable models are inadequate for determining what accounts for the changes in children's achievement scores. It was suggested that more complex models be used to determine the factors that are responsible for changes in children's achievement scores.