Full Idea
In Etchemendy's Interpretational Semantics (perhaps better called 'Substitutional') we keep the situation fixed and vary the interpretation; in Representational Semantics ('Modal'?) we keep interpretations fixed but consider varying situations.
Gist of Idea
Etchemendy says fix the situation and vary the interpretation, or fix interpretations with varying situations
Source
report of John Etchemendy (The Concept of Logical Consequence [1999]) by Stephen Read - Formal and Material Consequence 'Inval'
Book Reference
'Philosophy of Logic: an anthology', ed/tr. Jacquette,Dale [Blackwell 2002], p.238
A Reaction
[compressed] These are semantic strategies for interpreting logic, so they are two ways you might go about assessing an argument.
Related Idea
Idea 14181 Validity is where either the situation or the interpretation blocks true premises and false conclusion [Etchemendy, by Read]