In recent years, there have been many calls for engaging students in sensemaking while interpreting computerized representations. The US Department of Education has called for educators to close the “digital use divide” by supporting all learners to actively engage in sensemaking while working with technology. Literacy scholars have called for students to spend more time working with multimodal, digital, and interactive texts (Dalton & Proctor, 2008; Jewitt, 2008; Kress, 2009). The Next Generation Science Standards have called for students to spend more time interpreting models, including dynamic simulations. All these calls support the integration of computer-based simulations into science instruction. However, we still have much to learn about the enactment of simulation-based lessons in elementary classrooms. In this dissertation study, I investigated the enactment of simulation-based lessons in an elementary project-based science curriculum. The following research questions guided this study: (1) How do teachers support student sensemaking while working with simulations in the context of 3rd grade project-based science? Does this support, or student response to this support, shift across the three simulations? (2) What are the teachers' perspectives regarding the use of simulations as sensemaking tools? This study took place in two third-grade classrooms with a total of 2 teachers and 54 students across a full semester of project-based science instruction. The focal curriculum, Multiple Literacies in Project-based Learning (MLs) integrates science, language arts, and math while addressing all NGSS standards and select CCSS standards. Both teachers were experienced elementary school teachers with prior experience in the ML project. I used case study methods (Dyson & Genishi, 2005; Stake, 1995) to investigate how teachers supported student sensemaking while working with simulations. Data sources for this study included videos of classrooms observations, interviews with teachers, content assessments, artifacts, and the designed curriculum materials. Focal students were selected to represent the range of demographics and reading levels present in each class. With respect to the first research question, findings indicated that teachers used a variety of strategies to support student sensemaking during simulation-based lessons. These included: (a) identifying both conceptual goals and potential learning challenges prior to teaching with the simulation, (b) supporting students to articulate and share observations, predictions, reasoning and claims while working with the simulation, (c) supporting students to plan and conduct investigations using the simulation, (d) supporting students to interpret complex visual representations found within the simulations, (e) supporting student understanding of key scientific concepts, (f) repeating and extending student sensemaking, (g) guiding student use of the simulation by setting specific challenges or goals, (h) publicly recording student learning from the simulations, and (i) varying participation structures. With respect to the second research question, findings indicated that both teachers found simulations to be an engaging and beneficial learning opportunity. These findings have implications for curriculum design, simulation design, and teacher decision making while enacting simulation-based lessons.PHDEducational StudiesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/155050/1/easley_1.pdf