Evidence-based practices grounded in the learning sciences provide an opportunity for improved learning experiences in traditional in-person, as well as in hybrid and online environments. We advocate specifically that large-scale, online learning experiences can benefit from applications of the learning sciences. To that end, we participate in establishing a standard of practice in the development and design of Massive Open Online Courses (MOOCs). We present a description of how and why we use specific evidence-based learning science practices in a biochemistry MOOC with the intention to contribute to the discussion about the quality of online learning experiences, and lower the barrier for other practitioners seeking a scientific approach to course design. We believe that the application of evidence-based practices can make online learning experiences more rigorous and effective, and practitioners should optimize the use of these strategies through clever tests in specific contexts.Applying Learning Sciences to MOOC Design instructional design approach (Honebein and Sink 2012; Yanchar and Gabbitas 2011) to learning engineering, where we draw upon practices rooted in behaviorism, cognitivism, social learning, and constructivism, to address the challenges of online learning at scale.Here we document practices supported by the learning sciences that we readily implement in an online learning environment to contribute to conversations in the community of practice about evidence-based approaches to MOOC design. We hope these conversations lower the barrier for other developers of online and hybrid experiences to apply these methods. We found the following practices both robust from a theoretical standpoint, and practical in terms of application in our course design. We outline the evidence-based practices applied to course assets organized by function (pre-instruction, multimedia content, formative assessment, supporting resources, and summative assessment). However it is worth noting that many of the practices overlap in their usage (Figure 1). This article is an exposition on why and how to use the learning sciences in a specific context as a model for others, while highlighting a few strategies, and not an exhaustive review of these practices.