I am in the process of migrating a SP2010 solution to 2013.
Previously we had a CoreResultsWebPart configured to use a Search Scope, but as this functionality has been removed in 2013, the advice given is to use Result Sources instead.
I have set up a Result Source that behaves in a similar manner to the Search Scope, but how to I tell my web part to actually use the Result Scope?
EDIT:
This is the options I see when I edit the webpart