Science instruction in the early grades occurs infrequently, has been declining, and is often displaced in favor of literacy and math instruction. Coupled with U.S. students' continued mediocrity in science test led to a major overhaul of the science education standards, culminating with the Next Generaton Science Standards. This study focuses on the early grades where inadequate instruction in science is linked to negative attidutes and performance that persist across students' educational careers. The new standards provides an opportunity to investigage the impact of using an argument-based inquiry (ABI) approach on young children's scientific representational competencies as indexced by their ability to effectively convey their understanding of science knowledge in a multimodal summary writing task. The purpose of this dissertation is to examine science learning in K-2 nd grade in two studies, contrasting students who participated in argument-based inquiry (ABI) classrooms with those who participated in traditional science classrooms. At the conclusion of a science unit, students produced a summary writing assignment each spring to communicate their understanding of a particular science topic. A coding scheme was developed and validated to examine students' multimodal representational skills as indexed by their use of informational text features (i.e., Illustrations, Text Devices, Graphic Devices). Heirerarchical Linear Modeling (HLM) was used to asses growth within these features across time and in relation to teacher and child ABI experience was examined. All students' use of these features grew significantly across the project period and, for Illustrations and Text Devices, grew faster with each additional year of student ABI experience. The quality of teacher implementation as indexed by their years implementing ABI predicted more use and faster growth rates beyond those associated with child ABI experience. The influence of child and teacher ABI experience interacted significantly for Text Devices indicating that at least 18iv 24 months of experience by both were necessary to accelerate growth rates. Adoption of immersive ABI-learning environments in K-2 nd grade classrooms significantly and positively impacted student multimodal representational competence.