After decades of research endorsing inquiry-based learning, at best only moderate success has been noted in creating effective systemic implementation in K-12 classrooms. Thus, teachers need to be better equipped in how to bring this transformation to their own classrooms. Changing beliefs and overcoming external obstacles encourages the use of inquiry, but a clear, yet dynamic, instructional model is also needed for teachers to see the potential of inquiry-based instruction. The proposed 4E x 2 (read "4E by 2") Instructional Model provides such a model for learning that links strong conceptual understanding of content with inquiry learning experiences. The 4E x 2 Model integrates what we know and understand about inquiry-based teaching and learning with effective assessment and metacognitive reflection. These three constructs, formative assessment, inquiry instructional models, and metacognitive reflection, are foundational to the Model. A synthesis of research tied to these three constructs provides the justification of both the need for and the value of such a model. An argument for the formation of the 4E x 2 Instructional Model is made based on the coherence and the resulting synergy that occurs when these three learning constructs are united.