The purpose of this study was to systematically reflect upon my teaching practices, and to investigate the benefits of differentiated instruction using action research methods. This paper outlines the action research process, and is a case study examining the academic, social, and emotional progress of an advanced grade three learner involved in differentiated instruction activities. Pre and post assessments of this student include interviews, writing samples, math journals, and anecdotal records. Observations indicate strong support for differentiation in the primary classroom. Differentiated instruction promotes enthusiasm, motivation and confidence towards learning. The conclusions of this paper encourage the use of differentiated instruction techniques, and the ongoing self-reflection of teachers through action research methodology.