Carnegie Mellon University
September 16, 2020

CMU-Created COVID Early Warning App to Assist Campus Community

NOVID tracks coronavirus within your user network

By Jason Maderer

Jocelyn Duffy
  • Associate Dean for Communications, MCS
Carnegie Mellon University is encouraging faculty, staff and students to voluntarily download NOVID, a smartphone app that is uniquely designed to help track the spread of COVID-19. NOVID presents a new paradigm in exposure notification: it gives users a heads-up when someone in their user network, with up to 12 degrees of separation, has tested positive for the coronavirus. NOVID also allows people to anonymously self-report their own positive case. The app is another tool Carnegie Mellon is using to help track the coronavirus before it spreads.


NOVID Creator Po-Shen Loh describes the app's 12-degrees of separation.

NOVID was created by Po-Shen Loh, a professor in CMU’s Department of Mathematical Sciences in the Mellon College of Science. He and nearly two dozen students and alumni from across the university’s seven schools and colleges have been working on NOVID since March. Loh’s social enterprise, Expii, initially funded the app, which is available on Android and IOS for free.

NOVID uses a smartphone’s Bluetooth and ultrasound sensors to accurately and anonymously measure how far away other NOVID users are from you, as well as how long you’ve interacted with them. Once a user self-reports a positive case using the app, notifications are sent to their NOVID network, without displaying any personally identifying information.

Loh compares the process to the culturally popular “Six Degrees of Kevin Bacon” phenomenon, in which everyone seems to have a connection to the movie actor.

“The app tells everyone in the network how far away they are from a positive case — not in terms of miles or meters — but in social proximity,” Loh said. “NOVID tells you that you’ve been in touch with someone, who has been close to someone, who has spent time with someone who just tested positive. This gives everyone a sense when the ‘COVID temperature’ is getting hotter for them in particular.”


A brief "how-to" for using the NOVID app

NOVID is partnering with CMU’s University Health Services, which will provide an anonymous code to those who test positive. Once the code is entered into NOVID, notifications and advice are sent to the person’s NOVID network.

“It’s our hope that faculty, staff and students will use this app to keep themselves more informed about potential exposure to individuals with COVID-19 and to provide CMU leadership with more information as it makes science-based decisions throughout the semester,” said Daryl Weinert, CMU’s COVID-19 coordinator. “NOVID was created by our community and provides a unique opportunity as we prioritize the health and well-being of Carnegie Mellon.”

Unlike many COVID-19 apps in development or in use, NOVID is completely anonymous. The notification system doesn’t ask for personal information. Instead, each user is assigned a random number, which is used when their phone senses and communicates with other smartphones. The app doesn’t store GPS locations.

Loh created the system based on his research background in network theory.

“The foundation of NOVID is that if an anonymous network represents which devices are interacting with each other, it doesn’t matter who the users are. All that matters is that when there’s a signal of COVID positivity, an anonymous signal can alert the entire network, at long range,” Loh said. “Our first goal was to make an app that people wanted to use. Privacy and anonymity were imperative for that.”

Another way NOVID is different from many other apps is that it doesn’t rely solely on Bluetooth to measure distances between smartphones. NOVID adds ultrasound technology for greater accuracy. To date, NOVID is the only COVID app in the world that displays the estimated distance from other devices.

Carnegie Mellon users can enter the word “TARTANS” on the settings page of the app to join the NOVID CMU community. This provides access to university-specific COVID announcements, helpful links, surveys and follow-up advice, should a user test positive.

In addition to encouraging everyone on campus to voluntarily download the app, Carnegie Mellon is also requiring students based in the Pittsburgh area to complete a daily self-assessment survey each morning. Faculty and staff are also required to fill out the survey before coming to campus.