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[HE, 06-06-2019 11:17, Airport Lounge, D Gates, Schiphol Airport]

Dit bestand is bedoeld om extra inhoud in op te slaan, dat ik wegens tijdgebrek heb verwijderd uit de 45-minuten-versie.
Het wordt bewust nog nergens *included*. 
De 'nette' oplossing zou zijn het committen van deze inhoud op een nieuwe branch `english-60m`, maar het is nog maar 23 uur tot mijn praatje en daar wil ik mijn tijd nu niet aan besteden. 

Mocht er ooit dus een langere versie van dit praatje geaccepteerd worden, haal dan dit bestand erbij en verwerk de inhoud netjes in de eerder genoemde branch. 
De sessie kan nog verder verlengd worden door de demo's uit te breiden.

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<!-- #1: On measuring VCS popularity. Moved from `2-git.md`. --->

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[https://blog.gitprime.com/git-didnt-beat-svn-github-did/](https://blog.gitprime.com/git-didnt-beat-svn-github-did/) <!-- .element: class="attribution" -->

note:
Let's return to this chart one more time and allow me to address a final point:

* The numbers we see here are based on *relative search volume*. It is not the **actual** usage of the products. Version control system popularity is actually quite hard to measure! (more on this later)

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## Measuring Version Control System Popularity

* This is very hard.

note:
FIXME: dit verhaaltje kan beter. 
En schrijf wat naar het Google Trends-voorbeeld toe.

In Stack Overflow’s 2015 developer survey, 69.3% of respondents used Git, almost twice as many as used the second-most-popular version control system, Subversion. After 2015, Stack Overflow stopped asking developers about the version control systems they use, perhaps because Git had become so popular that the question had become uninteresting.

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<https://trends.google.nl/trends/explore?date=today%205-y&q=git,subversion,mercurial> <!-- .element: target="_blank" -->

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<!-- .slide: data-background-video="video/programming-language-popularity-stack-overflow.mp4" data-background-video-muted="true" data-background-size="contain" -->

<https://www.globalapptesting.com/blog/picking-apart-stackoverflow-what-bugs-developers-the-most> <!-- .element: class="attribution" -->

note:
FIXME: leg uit waarom dit niet de metriek is die je wilt. :-)

Wat betekent het als er veel vragen worden gesteld?
* veel gebruikers van de taal?
* veel onervaren gebruikers?
* de taal is moeilijk te leren / niet intuïtief?

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<!-- #2: What features would you suggest for a 'Git killer' product? -->

note:
Engage the audience in suggesting a few new features or improvements that would make them consider switching from Git.

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<!-- #4: What goes up, must come down. Moved from 1-preface.md -->

<!-- .slide: data-background="img/background/what-goes-up-must-come-down.jpg" --->

[Photo credit: Quang Le](https://quotefancy.com/quote/833239/Isaac-Newton-What-goes-up-must-come-down) <!-- .element: class="attribution" -->

note:
Now if the idea of "Change is the only constant" is valid in our industry, then so is the idea of "What goes up, must come down".
And although Newton (*point*) probably talked about an apple here, his quote can be applied to a lot of things, including:

* **airplanes**; 
  * I got here on an airplane, and it obviously came down. In a well-organised way, mind you!
* **Bitcoin prices**;
  * They went up, and they went down,
* **browser market shares**;
  * Everyone used Netscape, then it went down and we used Internet Explorer 6. Then Mozilla Firefox. Then Google Chrome.
* and maybe even **version control system market shares**. 
  * But I guess we'll find out!

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<!-- .slide: data-background="img/background/crystal-ball.jpg" data-background-color="black" data-background-opacity="0.5" --->

## What goes up must come down.

<blockquote class="explanation">
    <code>prediction variable #1</code>
</blockquote>

<https://www.pexels.com/photo/photo-displays-person-holding-ball-with-reflection-of-horizon-940880> <!-- .element: class="attribution" -->