explain xkcd - User contributions [en]

Talk:2169: Predictive Models

2019-06-29T18:42:14Z

Iggyvolz:

If you click on the comic, it opens a page with error 404. Looking at the URL, it says "At the July 28th meeting", which I assume is the prediction result to the title text suggesting that they will be 1 month late. [[Special:Contributions/162.158.106.174|162.158.106.174]] 17:13, 28 June 2019 (UTC)

: Fixsed it, my years of mediawiki knowledge have finally come to use. [[User:Iggyvolz|Iggyvolz]] ([[User talk:Iggyvolz|talk]])

In the HTML tag for the link (the <a> tag surrounding the comic image) after the link it says "cancel the meeting! our cover is blown" [[User:Everlastingwonder|Everlastingwonder]] ([[User talk:Everlastingwonder|talk]]) 17:21, 28 June 2019 (UTC)

In the [https://m.xkcd.com/2169/ mobile version], you can read «See also: [AT THE JULY 28TH MEETING][tab] "Cancel the meeting! Our cover is blown."» It leads to a 404, like the other examples in the comments here. [[Special:Contributions/172.69.44.136|172.69.44.136]] 17:31, 28 June 2019 (UTC)

This looks a whole lot like Gmail's [https://ai.googleblog.com/2018/05/smart-compose-using-neural-networks-to.html Smart Compose] [[Special:Contributions/172.68.206.76|172.68.206.76]]

Today GMail actually predicted the beginning of my mail correctly. I typed literally zero characters and it already knew how to continue. In the future, we won't even have to upload our brains to a computer, a backup will already be available there automatically. [[User:Fabian42|Fabian42]] ([[User talk:Fabian42|talk]]) 21:32, 28 June 2019 (UTC)

Not a backup, a simulation. [[Special:Contributions/108.162.219.184|108.162.219.184]] 04:46, 29 June 2019 (UTC)

On my Mac the title text only shows "WE WILL ARREST THE REVOLUTION MEMBERS" while on my iPad (where you long press to see title texts) long pressing only shows the link. Weird. Also someone remind me to check the link again on July 28. [[User:Herobrine|Herobrine]] ([[User talk:Herobrine|talk]]) 13:10, 29 June 2019 (UTC)

: On my Ubuntu system, both Firefox and Chrome display "WE WILL ARREST THE REVOLUTION MEMBERS" as the title text and "<nowiki>https://xkcd.com/[AT THE JULY 28TH MEETING][tab]</nowiki>" as the link target, which is also what's in the HTML source. Additionally, the HTML source is malformed, with quotes inside quotes in the href attribute. - [[User:Linneris|Linneris]] ([[User talk:Linneris|talk]]) 14:37, 29 June 2019 (UTC)

2169: Predictive Models

2019-06-29T18:40:12Z

Iggyvolz: Escape link in trivia

{{comic
| number = 2169
| date = June 28, 2019
| title = Predictive Models
| image = predictive_models.png
| titletext = WE WILL ARREST THE REVOLUTION MEMBERS [AT THE JULY 28TH MEETING][tab] "Cancel the meeting! Our cover is blown."
}}

==Explanation==
{{incomplete|Created by a PREDICTIVE MODEL THAT WILL BE FIRST AGAINST THE WALL WHEN THE REVOLUTION COMES. Do NOT delete this tag too soon.}}

{{w|Predictive text}} is a feature on many systems where as you type the system automatically suggests likely words or phrases to follow what you have written to that point. For instance, if you type "I'm heading" the system may suggest "home" or "back" as likely words to follow. Predictive systems usually use prior input to generate their predictions, so if you frequently type "Totally amazing!" the system will suggest "amazing!" every time you type "totally" even if you actually want to type "totally true" sometimes.

In the comic, [[Cueball]] is using predictive text to uncover a plot against his organization/government, but instead of using only his personal input, the system is using input from ''all'' users. By typing in an obscure phrase related to revolution and a meeting, he gets the predictive text algorithm to display where and when the next supposedly secret meeting will be held based on other users input. This works because it is unlikely that anyone else other than revolutionaries would be typing this phrase, thus the only data the algorithm has to predict from is the actual message from the revolutionaries on their next meeting. The caption of the comic is pointing out that systems which use prior input for predictive purposes in this way can end up leaking information that might otherwise be considered private.

As humanity adapts to a digital world, people are finding that their digital communications provide the illusion of confidentiality, with damaging results when the information leaks out. Real-life examples include a [https://www.bbc.co.uk/news/health-36391957 2016 British trainee doctor strike], where a technically-secure WhatsApp group leaked information to the press.

The title text shows the revolutionaries using the same technique. By typing in "We will arrest the revolution members" they are hoping that the algorithm will suggest the time and date of their planned arrest, since no one other than the authorities would be typing in that phrase. Pressing the key [tab] to autocomplete that text produces "WE WILL ARREST THE REVOLUTION MEMBERS [AT THE JULY 28TH MEETING]", and the revolutionaries then say "Cancel the meeting! Our cover is blown."

Both examples assume that the revolutionaries and the authorities would be talking about very secret information in the clear on a network accessible to their adversaries. In the real world people engaged in sensitive activities would communicate via code, encryption, or both, or would do so through secure channels. There is still the danger of secret information leaking via non-secret channels, however.

Although the comic title is "Predictive Models", the term {{w|Predictive modelling}} usually refers to computer programs that try to predict outcomes from data aggregation, such as reviewing health records to identify people most at risk from certain diseases based on weight, prior injuries, etc., before testing directly for the diseases themselves. This is similar to but not precisely like the example in the comic, since predictive text is using direct input to predict further input, while predictive modelling is using related input (such as make and model of a car along with driver acceleration patterns) to predict a different output (such as likelihood of a crash). Both predictive text and predictive modelling could leak information as the comic suggests, however. A famous example occurred in World War II. The Germans kept tank production figures a secret, but they gave items like engine blocks sequential serial numbers. The Allies wanted to know exact tank production figures, so they solved the {{w|German tank problem}} by using statistical methods to analyze the distribution of these numbers on captured vehicles. They were able to predict tank production figures extremely accurately, to the point they predicted 270 tanks in a month when 276 were actually built. Thus the secret information on tank production leaked.

Predictive text and the possibility to leak unintended information has been parodied on xkcd before in [[1068: Swiftkey]].

==Transcript==

:[Single panel with Cueball sitting at a desk typing on a laptop.]
:Cueball typing: Long live the revolution. Our next meeting will be at<span style="color:gray">|</span> [Predictive text tool suggests in grey text] <span style="color:gray">the docks at midnight on June 28 [tab]</span>
:Cueball: ''Aha, found them!''

:[Caption below the panel:]
:When you train predictive models on input from your users, it can leak information in unexpected ways.

==Trivia==
Clicking on a comic takes you to this page: [https://xkcd.com/%5BAT%2520THE%2520JULY%252028TH%2520MEETING%5D%5Btab%5D <nowiki>https://xkcd.com/[AT%20THE%20JULY%2028TH%20MEETING][tab]</nowiki>], which as of this moment only shows "404 Not Found". It is possible that [[Randall]] may add what he intends to add at a later date, most likely July 28, the date mentioned in the title text. The page will remain this way until then.
{{comic discussion}}

[[Category:Comics featuring Cueball]]

Talk:1729: Migrating Geese

2016-09-05T14:22:57Z

Iggyvolz:

Kevin sounds familiar, has he been in a previous xkcd? [[User:Mikemk|Mikemk]] ([[User talk:Mikemk|talk]]) 13:51, 5 September 2016 (UTC)

:I think Kevin is a reference to Home Alone. [[Special:Contributions/162.158.203.143|162.158.203.143]] 14:19, 5 September 2016 (UTC)

: [[1719: Superzoom]] also includes Kevin. [[User:Iggyvolz|Iggyvolz]] ([[User talk:Iggyvolz|talk]]) 14:22, 5 September 2016 (UTC)