Online Python Tutor: A 5-Year Retrospective
University of Rochester
October 30, 2014
Olin 107
Lunch will be served at noon.


Online Python Tutor ( is now the world's most widely-used educational program visualization tool. Over 500,000 people from over 165 countries have used it to collectively visualize over 5 million pieces of Python code. Many people are using this tool as a supplement to textbooks and MOOCs. In this talk, I'll cover the 5-year history of Online Python Tutor, which started out as a graduate student side project. I'll cover some technical details of its implementation, why it's been able to get such high usage numbers, and open research questions that I'm excited to explore moving forward!

Bio: Philip Guo is an assistant professor of computer science at the University of Rochester. His main research and teaching interests are in human-computer interaction, with a focus on designing the next generation of user interfaces for online learning. He received S.B. and M.Eng. degrees from MIT and a Ph.D. from Stanford. Outside of academia, he has worked as a software engineer at Google and an intern at Microsoft Research. Read about his adventures in programming and academia here:

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