Phonics is Phondamental to Literacy Acquisition: An Examination of the Impact of Systematic Phonics-Based Instruction and Whole-Language Approaches

This literature review investigates the effect of systematic phonics-based instruction and the whole language approach on early reading acquisition, specifically phonemic awareness, decoding, and orthographic mapping. Studies selected for this literature review contain empirical, qualitative, and quantitative research from 1998 to 2025, primarily focused on preschool through the primary grades and highlighting struggling readers. Theories, classical, and contemporary research consistently reveal that explicit phonics instruction is an effective instructional method to improve reading acquisition outcomes with effect sizes ranging from 1.0 to 2.0 (e.g., ; Johnston & Watson, 2005) and indicate that whole-language approaches lack efficacy due to English’s deep orthography. However, many studies are outdated, lack longitudinal data, and few examine implementation in preschool or bilingual settings. Survey data from Michigan educators reveal the implementation challenges contributing to the resistance in early childhood settings to systematic phonic-based instruction. This literature review highlights the necessity for classroom-based research that aligns with professional development and supports curricular decisions grounded in reading science. The results from this literature review illuminate the implications for theory, practice, and policy particularly aimed at closing the literacy gap for at-risk learners. The review concludes with a reflective application of the findings to instructional practice, offering insights for practitioners navigating the shift toward structured literacy.