Suggested by Granovetter "The strength of weak ties" (in The American Journal of Sociology, Vol. 78, No. 6., May 1973)as the ties in a social network that are not strong. Strong ties being those such as kin relations and close personal friends, weak as those such as conections met whiole at a party, or loose acquaintainces. The theory being built on by Putnam in Bowling alone as bridging social capital. The capital that ties groups together.