While support exists in the literature for the efficacy of computer-assisted instruction (CAI), possible dosage effects have rarely been investigated. Kindergarten students enrolled in a public school district in Idaho were randomly assigned on the class level to an experimental or control condition during the 2017-2018 school year. Students in the experimental condition used CAI, and students in the control condition received traditional literacy instruction for the same amount of instructional time. A standardized assessment was administered at the beginning and end of the school year. Students who used CAI demonstrated greater gains from beginning of year to end of year on all strands of the STAR Early Literacy assessment; however, gains were not statistically significant. Experimental students who used the program for at least 1,500 min throughout the school year significantly outperformed their control counterparts on all strands of STAR Early Literacy. These findings support the use of technology in teaching literacy skills to young learners and highlight the moderating effect that dosage has on learning outcomes. [This chapter was published in: "Smart Education and e-Learning 2019," edited by V. L. Uskov et al., Springer Nature Singapore, 2019, pp. 149-158.]