Over the past year, MOOCs (Massive Open Online Courses) have captured the attention of educators across the world. Many higher education institutions, including Penn State, are partnering with organizations like Coursera, Udacity, and edX to develop and deliver courses intended to serve tens of thousands of students simultaneously. While Penn State has been developing online courses for over 15 years, MOOCs provide new challenges due to their scale. Video-based instruction, peer assessment, and large-scale social learning must work flawlessly with little or no instructor intervention. Imagine a technical glitch or poorly designed interface multiplied by 50,000 students! Sound pedagogy combined with novel user experience design are essential to making a successful MOOC. In this presentation a group of experienced instructional designers and educational technologists will deconstruct MOOCs from a variety of providers and examine what works, what doesn't, and suggest strategies for designing compelling and intuitive educational experiences at massive scale.