Full Idea
We might think of strict ground as moving us down in the explanatory hierarchy. ...Weak ground, on the other hand, may also move us sideways in the explanatory hierarchy.
Gist of Idea
'Strict' ground moves down the explanations, but 'weak' ground can move sideways
Source
Kit Fine (Guide to Ground [2012], 1.05 'Weak')
Book Reference
'Metaphysical Grounding', ed/tr. Correia,F/Schnieder,B [CUP 2012], p.52
A Reaction
This seems to me rather illuminating. For example, is the covering law account of explanation a 'sideways' move in explanation. Are inductive generalities mere 'sideways' accounts. Both fail to dig deeper.