Classic Flaws

Bad Conditional Reasoning

When the person incorrectly reads the conditional reasoning chain, either by negating when they weren't supposed to, or by forgetting to negate when they should.

Bad Casual Reasoning

When the person claims that correlation equals causation. Remember the omitted options!

Whole to Part & Part to Whole

When the person assumes that an attribute of an individual applies to the whole group, or that an attribute of the group applies to an individual of the group.

Overgeneralization

When a person assumes that because one thing holds a certain property, everything else also has that property.

Survey Problems

Surveys are done with the greatest possible incompetence.

Common mistakes are: biased samples, biased questions, survey liars, small sample size, and other contradictory surveys.

False Starts

When the author assumes 2 groups are exactly the same in every way, except for the ones called out as part of the study.

(A question must say something like “The two groups tested were similar in all relevant respects except for regiment regimes." to not be a false start)

Possibility ≠ Certainty

If something isn’t necessarily true, it doesn’t mean it cannot be true (lack of evidence ≠ evidence of lacking). If something could be true, it doesn’t mean it must be true (proof of evidence ≠ evidence of proof).

Implication

Person A believes something, person B mentions a factual implication of that belief, and then assumes that person A believes that implication

False Dichotomy

Person outlines two possible options. They then eliminate one of the options and assume that the second option must be true. (They ignore the possibility of a third option.)

Straw Man

When someone responds to an entirely different claim than what was originally presented, and acts as if they responded to the claim presented.

Ad Hominem

When someone attacks the person making the argument, instead of the ir argument (causing them to conclude that their argument is false).

Circular Reasoning

Assumes that the conclusion is true and provides premises that prove it is true. Look for repetition & synonyms in premises and conclusions

Equivocation

When the meaning of a word changes halfway through the stimulus.

Appeal Fallacies

Turning an opinion into a fact, either by using an invalid appeal to authority or an invalid appeal to public opinion.

Irrelevant!

When the premises are entirely unrelated to the conclusion?

Percentage ≠ Numbers

Assuming that because a percentage went up, the total number went up. Or assuming that because a number went up, the percentage also went up. (These arguments always assume that the group size stayed the same size.)