Main Page

Explain xkcd: It's 'cause you're dumb.
Jump to: navigation, search

Welcome to the explain xkcd wiki!
We have an explanation for all 2475 xkcd comics, and only 39 (2%) are incomplete. Help us finish them!

Latest comic

Go to this comic explanation

Base Rate
Sure, you can talk about per-capita adjustment, but if you want to solve the problem, it's obvious that this is the group you need to focus on.
Title text: Sure, you can talk about per-capita adjustment, but if you want to solve the problem, it's obvious that this is the group you need to focus on.


Ambox notice.png This explanation may be incomplete or incorrect: Created by a LEFTY. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.

The "base rate" is a type of base probability, which a statistical probability can be based on. The base rate fallacy is a type of error in which people are presented with the rate at which something occurs throughout an entire population along with more specific information information about a subset of that population, and tend to ignore the whole-population information in favor of the specific information. For instance, imagine a disease that is present in 1% of the population, for which there is a test with a 5% false-positive rate. This test might be presented as "95% accurate", and so people who receive a positive result from such a test are likely to think they have the disease. However, someone who receives a positive test result has only a 17% chance of actually having the disease; a much more likely reason for the positive result, occurring in 83% of all positive test results, is a false (wrong) positive.

In this case, the joke is that 90% of people are right-handed, so Cueball's claim that right-handers commit 90% of base-rate errors is itself a base-rate error. Further, the pointer is held in Cueball's right hand, indicating that he too is right handed as he makes the base rate error.

Something similar occurs in 1138: Heatmap, where Cueball makes inferences simply based on a population map of the US, instead of statistical evidence.


Ambox notice.png This transcript is incomplete. Please help editing it! Thanks.
[Cueball standing in front of a screen, holding a pointer. The screen shows a bar graph with 2 bars, labeled "L" and "R". The "R" bar is significantly greater than "L".]
Cueball: Remember, right-handed people commit 90% of all base rate errors.

Is this out of date? Clicking here will fix that.

New here?

Last 7 days (Top 10)

Lots of people contribute to make this wiki a success. Many of the recent contributors, listed above, have just joined. You can do it too! Create your account here.

You can read a brief introduction about this wiki at explain xkcd. Feel free to sign up for an account and contribute to the wiki! We need explanations for comics, characters, themes and everything in between. If it is referenced in an xkcd web comic, it should be here.

  • There are incomplete explanations listed here. Feel free to help out by expanding them!
  • We sell advertising space to pay for our server costs. To learn more, go here.


Don't be a jerk.

There are a lot of comics that don't have set-in-stone explanations; feel free to put multiple interpretations in the wiki page for each comic.

If you want to talk about a specific comic, use its discussion page.

Please only submit material directly related to (and helping everyone better understand) xkcd... and of course only submit material that can legally be posted (and freely edited). Off-topic or other inappropriate content is subject to removal or modification at admin discretion, and users who repeatedly post such content will be blocked.

If you need assistance from an admin, post a message to the Admin requests board.