Bias and fallacy quiz

About this tool

Bias and fallacy quiz: what it is and how to use it

The bias and fallacy quiz is a free ten-question game. Each question is a short, made-up everyday scene showing one common slip in reasoning, and you pick its name from four choices. After each answer you see why the scene fits, the definition from our article and a link to the full entry. It runs in your browser.

Fallacies and biases: what the two words mean

A fallacy is a slip in the reasoning behind a claim. The Internet Encyclopedia of Philosophy puts it in one line: "A fallacy is a kind of error in reasoning." The study of them is old: the Stanford Encyclopedia of Philosophy says it "begins with Aristotle's work, On Sophistical Refutations", which lists thirteen types.

Our logical fallacies cheat sheet starts from one point worth keeping: a bad argument can still land on a true conclusion. Spotting a fallacy tells you the argument does not support its conclusion. It does not tell you the conclusion is false.

A bias works on judgement rather than on an argument. One review describes cognitive biases as "systematic and common tendencies, inclinations, or dispositions that skew or distort decision making processes". Not every famous bias came back the same size when psychologists ran the studies again, so the quiz uses five that our cognitive biases article found coming back, in full or smaller, and leaves out the ones still argued over. Anchoring and hindsight bias held up; framing held up at about half the original size; sunk cost replicated as a small effect in a hypothetical scenario; and confirmation bias is real, but a family of effects rather than one finding.

How to use it

1. Read the scene. Each one is a short everyday moment we made up; none is about a real person.
2. Pick the name you think fits from the four choices. On a keyboard, keys 1 to 4 pick an answer.
3. Read what comes back: our reading of why the scene fits, the definition from our article, a note on when the same move is fair where the article gives one, and a link to the full entry.
4. Press Next question, or Enter. After ten you see your score and a short list of the ones worth another look.
5. Play again for a new mix. Your best round stays in this browser until you press Delete everything.

An example

One scene: a housemate suggests turning the heating down by one degree, and another replies, "So you want us all to freeze in the dark all winter?" The name that fits is the straw man: a small, reasonable suggestion is swapped for an extreme one that is easier to knock down.