Independence of Smith-dominated alternatives (ISDA, also known as Smith-IIA) is a voting system criterion which says that the winner of an election should not be affected by candidates who are not in the Smith set.
[citation needed] Schulze and Ranked Pairs are independent of Smith-dominated alternatives.
Any voting system can be forced to satisfy ISDA by first eliminating all candidates outside the Smith set, then running the full algorithm.
Smith-IIA can sometimes be taken to mean independence of non-Smith irrelevant alternatives, i.e. that no losing candidate outside the Smith set can affect the result.
[citation needed] This differs slightly from the above definition, in that methods passing independence of irrelevant alternatives (but not the Smith criterion) also satisfy this definition of Smith-IIA.