The purpose of 100 strangers is to get photographers to step out of their comfort zone by photographing strangers(with their consent) they have never met before and get a piece of information about their life.
They will choose someone they have never met before, hence the name 100 strangers. Many photographers will choose who they photograph for their project based off looks; such as if they have a unique sense of style, or stick out from the surrounding people. But some will use just average everyday looking people so when other people are viewing their photos, they can have a sense of connection.
#23 Elen by Barbara AsBoth
Stranger #8 Kevin Lee Light by David Weir
#19 Lucas by Ben Hinceman
#97 Rebecca by Stephan Jessop (London, England)
Stephan Jessop(Round 1): https://www.flickr.com/photos/sbjessop/albums/72157638858225106
Stephan Jessop(Round 2): https://www.flickr.com/photos/sbjessop/albums/72157651808910793
Map of England where Stephan Jessop shot his project
David Weir: http://weiry.com/100strangers/
Map of Los Angles where David Weir Shot his photos