Skip to content

Why do we believe that our exposure notification app will help?


Q: Why do we believe that our exposure notification app will help? 

A: A good start is that we know that traditional contact tracing can stem COVID-19 transmission (at least as practiced in the U.K.) We know this because some economists took advantage of a “natural experiment”, which is the term scientists use when they make lemonade out of a horrible error. The horrible error was that contact tracing data was processed via an Excel 2007 .xls file, which truncated rows and so, deleted data. Regions in the U.K. whose contact tracers lost more data had more virus transmission than regions that lost less data. These results are nearly as good as a gold-standard randomized trial in proving that contact tracing helps.

What about digital exposure notification? In some ways, it is better than traditional contact tracing. It is faster, it catches contacts that the primary case doesn’t know personally, and its privacy protections take some of the shame out of the process, (e.g. about reporting the names of everyone at a large social gathering that you know that you know you shouldn’t have gone to and are embarrassed to admit to). Automated digital solutions are also less prone to break down when there are a lot of cases. And now, we have direct evidence from the U.K. that notifications are going out to the right people, and have likely averted thousands of deaths and hundreds of thousands of infections.

Where digital exposure notification tends to be weak is on the human side. It isn’t enough to notify somebody that they were exposed - they also have to change their behavior afterwards. We need to tell them what to do next, and persuade them to do it.

Human-centered design is a guiding principle for our app, in a way that makes it stand out from other digital solutions. Should you get notified of a dangerous exposure, our app will tell you what day to get quarantined until, what day to get tested, what symptoms to look out for, and anything else that your local community recommends. Each recommendation is coupled with a simple one-click link: to schedule that test with a local provider, or to learn more about a specific point. Similarly, when you share a diagnosis using our app, you will see recommendations, specific to your local community, as to what to do next and what resources are available. We don’t think it is an optional extra to have the app give specific, hyper-local recommendations — we think it is essential functionality. It doesn’t help to notify someone of exposure if all you do is worry them. We need to help people change their behavior in ways that will stop disease transmission, but without making life unnecessarily difficult or alarming.

Some communities include website links where you can register yourself with local contact tracers as an infected or as an exposed person. Traditional contact tracing and digital exposure notifications aren’t alternatives — they work best together. The flow of information is currently too slow as it goes from test providers to central public health authority databases and back to local contact tracers. We bypass these delays, going directly from test providers to individuals to local contact tracers. We not only offer a platform for digital exposure notification, but we also help traditional contact tracing work better and faster.

Have a question? Ask the professor: