What is 20 Day Stranger?

20 Day Stranger is a mobile application that exchanges two individual’s experience of the world, while preserving anonymity on both sides.  You will never know who your stranger is, or exactly where they are, but we hope to reveal enough about them so that you can begin to build an imagination of their life... and more broadly the lives of strangers everywhere.


Who is behind this project?

This is a project from Playful Systems at the MIT Media Lab in collaboration with the Dalai Lama Center for Transformative Ethics and Values at MIT


What are the motivations behind the project?

We hope that the experience of spending 20 days with a window into the life of a complete stranger will extend more broadly to how you feel about the strangers on a daily basis.


How does 20 Day Stranger work?

The application automatically gives your stranger an idea of where you and what you are doing are based on your GPS location and your device’s movement.  


Does that mean some stranger will know exactly where I am at all times?

No.  We give your stranger a broad idea of where you are based on an image of the place that is publicly available and taken by someone else.  If you are at a park, we will let your stranger know just that.  We will never share the name of the park, or the name of the city you are in.


Is 20 Day Stranger anonymous?

Yes.  20 Day Stranger does not require a user signup or login.  And we never ask you to share any identifying information about yourself to your stranger.


Who has access to this data?

The only people with access to this data are the authorized developers at the MIT Media Lab in the Playful System’s group. Even those developers, however, do not know anything about the participants in the project (including names, phone numbers or the like.)


What do you do with the data?

Data generated by our software is only used for the purposes of the 20 Day Stranger experience.  After the 20 day period, all the data will be deleted from our servers.  The only data point that we will store for a longer period is the final log at the end of the 20 Day period to track usage and geographical distribution of the app. Perhaps it’s unnecessary to say so, but this data will never be used for any purpose except for this unique application, during the 20 days that you are using it. It will never be stored further, sold, or used in conjunction with any other parties or projects.


Where does the data go?

Your data is stored in a protected database for the duration of a single connection with a stranger (20 days).  After the 20 day period, all data is erased except for your very last log.  We do this so that we can have a cumulative record of all stranger connections.  Again, these logs are anonymized.


Will this work on my phone?

Our aim is to bring this experience to as wide an audience as possible.  The current release is for iPhone and Android devices.  We hope that you are able to participate.


I have a personal phone and a work phone, which one should I use?

We recommend using the device that you use, and is on you the most.


Who am I going to be paired with?

We are doing our best to match people who are as far from each other as possible.  At the same time, we don’t want people to have to wait too long to be paired.  With offices all over the world, you will most likely be paired with someone who lives in a different country.


Will this drain my phone’s battery?

20 Day Stranger is optimized to run in the background of your device using 1% of your battery/hour.


How much data will this use?

20 Day Stranger uses very little of your data.  The application generates intermittent logs when a data connection is available.  A log is equivalent to sending approximately 1 email that contains only text.