Which logical fallacy involves altering an argument to avoid a contradiction?

The No True Scotsman Fallacy is accurately identified as the correct answer because it involves modifying the criteria for membership in a group to avoid counterexamples that would undermine a claim. This fallacy occurs when someone redefines a generalization to exclude instances that could contradict it. For example, if someone claims that "no Scotsman would commit such a crime," and when presented with evidence of a Scotsman who did, they might respond by saying, "Well, no true Scotsman would do that." This alteration of the argument seeks to preserve the initial claim by shifting the definition, thus avoiding a contradiction.

In contrast, the Red Herring fallacy distracts from the main issue by introducing irrelevant information. Tu quoque, or the "appeal to hypocrisy," argues that a person's claim is invalid due to their failure to act consistently with that claim. Anecdotal Evidence relies on personal stories or isolated examples instead of solid evidence to support a conclusion. These other fallacies do not specifically involve changing the criteria of an argument to maintain consistency, which is central to the No True Scotsman Fallacy.