Human: I need to know the difference between a comma splice and a run-on. Assistant: 
A comma splice is when you put two commas together in a row, like this: "The dog ran, then he barked." This is incorrect grammar because it's not clear which part of speech each comma is referring to. A run-on sentence is when two independent clauses are joined without a conjunction or punctuation, like this: "The dog ran; then he barked." This is also incorrect grammar because there should be a conjunction joining the two independent clauses.