This research aimed at determining whether the Illuminative Evaluation Model of Parlett & Hamilton (1972) would be able to reveal invisible realities, disentangle complexities or isolate the significant from the trivial events in order to provide an informed account of the new K-12 Grade 1 Mathematics Curriculum as implemented in a private school in Bulacan, Philippines. Specifically, following the model’s 3-step framework, (1) Investigate, (2) Inquire Further, and (3) Explain, this research looked at the school’s instructional plan and learning milieu to uncover problems encountered upon implementation of the curriculum, how these have affected pupils’ learning, and what could be done for future curriculum improvement.

This paper concluded that the Illuminative Evaluation Model was able to unravel the complexities that a curriculum encounters upon implementation, including those that were not foreseen during the curriculum design. The model was able to illuminate the wide array of factors that came forth during curriculum execution, those invisible realities that could not be identified by the traditional evaluation methodology of looking into the scores of the pupils. The model proved to be an effective evaluation tool. Although using it requires much time, the wealth of information gathered after the course of evaluation, not just in the teaching-learning aspect, but also curricular, structural, and evaluative aspects, is beneficial for a school’s curriculum improvement and institutional development.