<p>The demand for successful online education has risen sharply within the last decade, prompting researchers to investigate effective teaching strategies. However, replicating the best practices of traditional in-person instruction in an online class has proven challenging due to missing elements in the online modes of instruction. We observed that online classes lacked sufficient instructor scaffolding, peer collaboration, and instructor feedback. In this study, we hypothesized that implementing these teaching strategies would help bridge the gap in student performance between online and in-person instruction. We administered four curricula designed for an online introductory biology course for non-majors: three focused on implementing one designated missing element, and the fourth implementing all three consecutively. In every case, our online students performed inferior to the in-person students when looking at unit exams, final exams, and final grades. These results serve as a preliminary look at the inability of online courses to authentically replicate essential aspects of in-person instruction. We offer suggestions for educators and researchers to design optimal online learning experiences in the future.</p>