explain xkcd - User contributions [en]

Talk:2023: Y-Axis

2018-07-23T21:00:34Z

162.158.234.40:

"There are four kinds of lies: lies, damned lies, graphs, and statistics." [[User:Andyd273|Andyd273]] ([[User talk:Andyd273|talk]]) 13:37, 23 July 2018 (UTC)

To me this graph stands out as having something very wrong far more than those that limit the y axis to a short range. If the grid lines were several shades lighter however... [[User:PotatoGod|PotatoGod]] ([[User talk:PotatoGod|talk]]) 15:44, 23 July 2018 (UTC)

Also I wonder if anyone can find a legitimate (non-misleading) use for the semi-semi-log plot? I’m sure there’s some scenario where it could be useful. Perhaps showing the population growth of a species, then when the growth levels out at the maximum sustainable level for its environment (I forget the proper term from high school biology) showing more detail of the small population changes or something like that? [[User:PotatoGod|PotatoGod]] ([[User talk:PotatoGod|talk]]) 15:52, 23 July 2018 (UTC)
:Frankly, it would be better to just use 2 separate graphs. Even if you explain to the reader that the scale changes mid-way, it would still be misleading on the subconscious level. The whole point of visualization is to allow the reader to utilize that sweet auto-processing power of our brains so that we don't have to think about what we are looking at too much. [[User:Jaalenja|Jaalenja]] ([[User talk:Jaalenja|talk]]) 17:59, 23 July 2018 (UTC)

Are there any IRL examples of this type of plot trick? I've never seen it

At first I thought the X-axis was logarithmic, because it lacks labels. This can also cause the sudden data jump.

1586: Keyboard Problems

2018-07-09T21:10:30Z

162.158.234.40: /* Explanation */

{{comic
| number = 1586
| date = October 5, 2015
| title = Keyboard Problems
| image = keyboard_problems.png
| titletext = In the future, a group of resistance fighters send me back in time with instructions to find the Skynet prototype and try to upgrade it.
}}

==Explanation==
This comic parodies how people diagnose and solve computer problems. Cueball and Megan are trying to solve a keyboard issue, but are somewhat incompetent at diagnosing the issue. Cueball in particular blames a broken keyboard on software or a keyboard virus.

In the comic, [[Cueball]] complains that some keys in his keyboard don't work. Generally speaking, this could be due either to a software problem (e.g. the keyboard driver not working properly, or some program ignoring keypresses) or to a hardware problem (the keyboard is physically damaged, e.g. because of dirt under the keys).

If the problem is in the software, booting from a different operating system (e.g. an external recovery disk) should solve it, as the computer would no longer be using the faulty software. Conversely, if the problem is in hardware, changing the keyboard should solve the problem as the new keyboard would no longer be physically damaged (and has no dirt under the keys).

However, the problem stays there after booting from an external recovery disk (so it's not a software problem) and it has "followed Cueball since his last computer" (i.e. the problem persists after changing to a new laptop with a new keyboard, so it's not a hardware problem). Cueball is (reasonably) puzzled.

[[Megan]] seems to be used to Cueball's computer behaving strangely, and she doesn't even attempt to explain or solve the problem. The only explanation she needs for the problem is that "it's Cueball's computer". The characters in this comic are probably the same as in [[1084: Server Problem]], [[1316: Inexplicable]], and [[349: Success]].

Both Cueball and Megan are entirely clueless to the fact that the issue is likely a hardware issue with the keyboards, rather than a virus that spreads between computers. It's possible Cueball uses the computer in a dirty environment with food or dust clogging up all of his keyboards. It may also be a case of {{w|User error|PEBKAC}} --as in, Cueball pounding the keys in the same way on both keyboards, and breaking the same keys. Blaming such a broken-key problem on software or a virus is completely absurd.

The last panel is a reference to {{w|The Terminator}}, a 1984 movie often referenced in xkcd. In the movie, the artificial intelligence named Skynet initiates a nuclear war, destroying most of humanity, then it sends killing machines to finish the rest. These include flying drones - Megan suggests that if such robots come to Cueball's vicinity, they will (physically) crash since computers around Cueball can't seem to ever work properly, and so hiding in Cueball's house she should be safe from the robots.

The title text refers to main plot of the movie and its sequel {{w|Terminator 2: Judgment Day}}. As Skynet's army is losing the battle against the human Resistance movement, it finds a way to send a humanoid robot {{w|Terminator_(character)|T-800}} back in time to kill the mother of the Resistance's leader. The Resistance in turn sends {{w|Kyle Reese}} back in time to protect her. In the sequel, the situation repeats with the more advanced {{w|T-1000}} being the killer and a reprogrammed T-800 being the protector of the child (the future leader). Along the way, they manage to destroy the research lab where Skynet hardware is to be born in the future. The title text suggests an alternative mission into the past, sending Cueball back in time and using his power to cause Skynet to malfunction instead of destroying it physically (as Skynet was created later anyway, despite the destruction of the research lab).

==Transcript==
:[Cueball sits between two laptops. Megan stands behind him.]

:Cueball: Keys on my keyboard keep failing, even when I boot from an external recovery disk.
:Megan: Sounds like it's hardware, then.

:[Cueball moves over to the laptop behind him.]

:Cueball: Yeah... except the problem followed me from my ''last'' computer.
:Megan: You have the most ''bizarre'' tech issues.

:[Cueball picks up the keyboard from the rear computer and plugs it into the one in front of him.]

:Cueball: It must be spreading via keyboards. This one won't work with ''any'' computer now.
:Megan: When the robot apocalypse happens, I'm hiding out in your house. Any Skynet drones that come near will develop inexplicable firmware problems and crash.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Computers]]
[[Category:Cueball Computer Problems]]

Talk:1725: Linear Regression

2018-04-10T09:43:16Z

162.158.234.40:

It also seems likely that the teapot refers to the Utah Teapot (https://en.wikipedia.org/wiki/Utah_teapot). It was one of the first complex 3D objects defined for CGI rendering, and has seen countless uses since. Notably in the Pipes screensaver, and early SIGGRAPH papers where it was rendered along side the 5 platonic solids as if it belonged with them.
[[User:Dkfenger|Dkfenger]] ([[User talk:Dkfenger|talk]]) 17:10, 26 August 2016 (UTC)
: I'm not sure I follow. How do you reach that conclusion? Given that the concept of constellations (and thus stars) is clearly shown in the comic, it seems much more likely to me that he was referring to Russell's Teapot and not to a computer rendering (if there was any reference at all). The fact that that shape could abstractly resemble a teapot may be all that there is to it. :) [[User:KieferSkunk|KieferSkunk]] ([[User talk:KieferSkunk|talk]]) 18:06, 26 August 2016 (UTC)

I think that the teapot is a reference to the constellation Sagittarius. This seems most likely to me as the reference is to a constellation that looks like a teapot despite ostensibly being something else. Sagittarius is a constellation that is supposed to be an archer, but many people see it as a teapot instead. (http://www.space.com/30274-constellation-sagittarius-archer-dipper-teapot.html) [[User:Harperska|Harperska]] ([[User talk:Harperska|talk]]) 19:27, 26 August 2016 (UTC)

I think it looks like a alcohol drink with the little umbrella sticking out. [[User:Mikemk|Mikemk]] ([[User talk:Mikemk|talk]]) 06:25, 27 August 2016 (UTC)

Based on what is an R^2 value of 0.06 significant??? I'm removing that. [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 20:59, 26 August 2016 (UTC)
: Oops, misread it! I read "insignificant" as "significant". [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 21:00, 26 August 2016 (UTC)

The teapot mention may just be a joke, not a reference. {{unsigned ip|141.101.98.114}}

did someone check if it really was a Rsquared of 0,06?[[Special:Contributions/141.101.104.67|141.101.104.67]] 20:56, 27 August 2016 (UTC)

:Asuming the top left of the image as 0/0 and measuring in pixels I get f(x)=-0,135x + 124,8 with R²=0,0197, calcuated with LibreOffice. The line in the image has f(x)=-0,094x+125. If I change a single point by one or two the R² value varies from 0,0195 to 0,0199. If I substract 10% of the x value from the y value R² increases to 0,0574. So I think R²=0,06 is a little bit inaccurate, but not completely wrong. --[[Special:Contributions/162.158.83.228|162.158.83.228]] 19:01, 2 September 2016 (UTC)

::I think R^2 = 6% is very inaccurate if the true R^2 = 2%. [[Special:Contributions/108.162.219.56|108.162.219.56]] 00:07, 3 September 2016 (UTC)

Does anybody know of any real-world examples of a similarly low R^2 given in genuine research? It would be worth mentioning their existence if we can find one. [[User:Cosmogoblin|Cosmogoblin]] ([[User talk:Cosmogoblin|talk]]) 18:03, 28 August 2016 (UTC)
: In published research? I don't recall any. In submissions for review? At least twice. And of course one case where this comic could and should be used as an educational drawing - student reports, master's theses, etc. I've seen "conclusions" drawn from weaker data in those, far too many times for my mental health...--[[Special:Contributions/162.158.86.119|162.158.86.119]] 09:32, 30 August 2016 (UTC)

Rex is also Latin for king, which may be related in the context of constellations. {{unsigned ip|172.68.11.81}}

This is irrelevant to the humor of the comic, but I fixed the paragraph on confidence intervals because it contained at least three misinterpretations (I have a MSc in statistics). The phrasing can be improved if needed. Don't worry though, [http://www.andrewgelman.com/2017/12/28/stupid-ass-statisticians-dont-know-goddam-confidence-interval even experienced statisticians get it wrong sometimes...] [[Special:Contributions/162.158.234.40|162.158.234.40]] 09:43, 10 April 2018 (UTC)