Independent (or at least autonomous) flows of activity/concern attention/interests that John Kingdon used in his Multiple Streams Approach.
There are three well-established ones – problem, politics and policy. Howlett et al have posited two additional ones – process and programme. It’s not yet clear if they will catch on. Some (cite – Zohnholfer et al) think that they are not needed and hurt the parsimony….
marchudson.net 