How Google's PageRank Algorithm Works

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Google's PageRank algorithm is one of the most important algorithms on the Internet. The algorithm attempts to rank pages according to their importance. But what does it mean for a web page to be "important"? In this video, we explore the "random surfer" model, which allows us to calculate a page's PageRank by simulating a random surfer who browses the web one page at a time.
0:00 PageRank
1:39 Random Surfer Model
3:40 Damping Factor
***
Spanning Tree is an educational video series about computer science and mathematics. See more at spanningtree.me
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Spanning Tree is created by Brian Yu. brianyu.me/
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28 июл 2024

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Комментарии : 86

@nicolasagustin3022 4 года назад

Very good explanation, congratulations. The animations make the whole topic more understandable and clear. Greetings from Argentina

@Kanibulus Год назад

Vamos carajo!

@rajahamza5996 2 года назад

Thank you so much for this perfectly explained video - i have been trying to understand this, but now looking at your work, with the animations and simply explanation etc. has helped me so much.

@ohiocoder8313 2 года назад

even with the random surfer, what stops me from creating 1000s of websites to affect the rank of my website. Maybe it lessens it a bit but I don't think I understand if the random surfer helps in that matter that much. If the "random surfer" was real users going through websites and we somehow kept track of that, then I would understand more

@weckar Год назад

The issue is that nothing links to those random pages you created, so the surfer landing on those in the first place is quite unlikely. In reality, the damping factor is much higher than .85, so you have almost no chance.

@gsittly Год назад

You can. But not all websites on one server oder IP address, because then this is counter productive and you will be deranked instead

@gabenugget114 Год назад

@@weckar but still, he can make a loop

@weckar Год назад

@@gabenugget114 doesn't matter and in fact reduces the visibility of your main page

@jacksondeane1629 Год назад

@@weckar what if you linked to all of the random ones from your main one

@nikhilsrajan 3 года назад

Great video man. Simple short and clear explanation.

@tanzeelazam9552 2 года назад

Thank you for explaining it in such an easy and understandable manner.

@krittaprottangkittikun7740 3 года назад

This video is really good. Thanks for making this!

@PedroContipelli2 2 года назад

Clear, concise, amazing!

@CosmicAlphonso 4 года назад

Best explaination so far.

@ravibond6467 3 года назад

Very nicely you have explained this.

@NoNTr1v1aL Год назад

Absolutely amazing video! Subscribed.

@justlooking9802 Год назад

That iconic voice from Bryan Yu. You're a legend sir!

@snkarbhr 3 года назад

I find your channel unique and informatic

@learningontheway4483 3 года назад

Very well explained!

@MichaelOConnor247 3 года назад

You are a hero, great explanation

@howardoneal598 2 года назад

Very clear. Much love!

@aakashgyl Год назад

Very nice and easy to understand explanation

@ommule4999 2 года назад

Great video and animation !! Keep Up !

@bangvu2127 3 месяца назад

Thanks for a great explanation

@felipersa3809 4 года назад

very good!!

@jtromsness Год назад

Thanks for this video! Would love to see a visual factoring content prioritization. How prioritizing subsidiaries and paid advertising would change the outcome of the results

@japroz 3 года назад

Great video. You should also teach about algorithms in you web programming course at Harvard

@UnscriptedM01 3 года назад

No words yo Admire you for such a Mater Piece of video

@nikeshdahal4117 2 года назад

nice explanation .

@safiqlodi834 4 года назад

Simple and clear explanation, :) ! By the way how did you create that animation? Can you share that?

@shehzad5495 2 года назад

Good explanation ⭐⭐⭐⭐⭐

@mkd0x 3 года назад

Wtf how is this channel so freakin good. I expected at least 2 million follower. I'm deeply shocked !!!!!!!!

@coordinates_ 3 года назад

🙄

@investradelearn Год назад

great vid thanks!

@mohanchoudhary2582 3 года назад

simply awesome......

@moronsaltable Год назад

This makes it a lot simpler to understand than what my teacher explained to us in class. Instead of using pigeons he used Ruphus cucullatus

@harsh9558 Месяц назад

Very interesting

@justinshin6867 Год назад

Nice video, but how does the random surfer model help solve the issue of creating lots of websites to change the rank of your own website (a problem you yourself brought up)?

@Nathan-cz8uk Год назад

I think the idea is: those pages (the ones created to link to the target website) would not have many pages that link to them, so the random surfer wouldn't be sent to them much, meaning there wouldn't be many more visits to the target page.

@anirudhsilverking5761 Год назад

@@Nathan-cz8uk Bingo

@jarivuorinen3878 Год назад

@@Nathan-cz8uk But how do you then introduce completely new page that has nothing linking to them and get it searchable? Random surfer only has random chance to land on that page that's only 1/X and X being every single page that exists in the space that random surfer can land to. Can you then introduce one thousand pages that cross-link each other so that random surfer in total has >1000/X change landing on any of those? Would that cause an issue that then your most ranked page will be random out of those 1000 you created? Those could of course all link to less than 999 of your pages and every page still linking to your first page that you intend to get shown for in search results, that would make it most ranked out of that set anyway.

@maranza1974 3 года назад

It’s more easy calculate the % with the algebric Matrix of the Number of the links

@theonewhobullies 3 месяца назад

damn, had to study the mathematics of it in Univ to understand it, you did it in a few minutes.

@BenjaminLiraLuttges Год назад

Can someone explain how pagerank is different from eigenvector centrality?

@guillermoelnino Год назад

Forgot on the backend google basing "relivance" based on ESG score.

@oscuritowaffu6345 Год назад

that just feel very slow to compute due to the big number of web pages and the iteration it takes to converge to a stable pagerank value

@stanleydodds9 Год назад

Isn't it easier to just describe this as a discrete time markov chain problem? You basically just want to set up a transition matrix where unlinked pages have a transition probability of 0 or something very small according to the damping factor, and all the linked pages have equal probability. Then you just want to find a steady state, so basically just look at the eigenspace corresponding to eigenvalue 1. This also neatly encodes the first problem; if you have no damping, you'll get a big multidimensional eigenspace if there's multiple connected components. But if you introduce some damping, the eigenspace will be 1 dimensional; you'll have a unique stationary state, which is exactly the importance ranked by this monte-carlo algorithm.

@UmaROMC Год назад

That sure sounds easier! Or not, I don't really know. Maybe the dude/dudette that came up with it was worse at math than you? Remember that lots of programmers and 'software engineers' don't really have math degrees.

@Khunkurisu Год назад

Ah yes cause everything you just said is definitely easier to follow for the average person. 🙄

@MeowfaceMusic Год назад

Nice! Ah, so much better trying to focus in on your voice and the concepts without any audible distractions. 👌🏻

@abhishekjaiswal-ub2zs 6 месяцев назад

Simply, Lovely. In a layman's language :)

@cuboembaralhado8294 Год назад

You could create lots of pages of your own to link to the main page, yes, but you could also pay other more prestigious pages to link to your page instead. If they are on the track of the random surfer, you'll be too

@videopsybeam7220 9 месяцев назад

I'd thought about this too. You'd have to hope that these pages are prestigious enough that a) they don't need your money, or b) they wouldn't want to risk hurting their reputation by linking to a disreputable page.

@bibop224 Год назад

A page importance is relative to what is searched, it's not absolute. So how does it rank the importance of pages for any given search query?

@fanskucing597 2 года назад

O_o I've never been deep in math and just know how to use it in program I didn't know how it works this is interesting

@jennyzeng7015 Год назад

Does the "random surfer" refer to a real user or a googlebot?

@SkeleCrafteronYT 2 года назад

This video should be shown b4 all data algo courses lmao

@antipoti Год назад

There is a lot more to google search these days than just the linking. All kinds of content analytics and AI is involved. But yea, it all started with the links.

@kebman Год назад

Hm looks kinda similar to a Markov model.

@milakohen630 Год назад

. simplicity is an amazing skill 😊 please make videos on AI 😊

@hasanabbas1555 10 месяцев назад

Is this brian wu from cs50??

@chriszablocki2460 2 года назад

I'm interested in controlling my RU-vid content more. Does anybody have any helpful advise on how I can do that?

@bindukhadka454 4 месяца назад

✨

@0q9s2 Год назад

The real question is what if I create hundreds of pages that all link to each other, possibly linking to one page more often than any other?

@Husain_bohra Год назад

Still the problem is that for a random surfer The damping factor is much higher So the chances of the surfer landing on any of the pages is negligible

@virtualbro8571 3 года назад

Mark Zuckerberg explaining Google's algorithm....wow...nice

@griffinshorts785 Год назад

Lol

@travisweedon1234 2 года назад

I know this voice! CS 50 lecturer?

@planktonfun1 Год назад

You ever noticed that google search isn't good as its used to be?

@tiichun 3 года назад

yo.... bando 3sj 3him up

@michaelvangulik85 Год назад

What if my website doesn't have many links and stays that way for many months? And what if my site isn't important (due to no links) but contains relevant keywords that more important sites don't contain? (this is a very in depth comment.)