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- Hacker News
- Let's not forget that PageRank unintentionally spawned the SEO industry.by saltysalt
- Also PageRank as a Markov chain
[0] https://math.libretexts.org/Bookshelves/Linear_Algebra/Under...
by yu3zhou4 - As, I think, Page points out in the patent, PageRank's idea comes from Science Citation Index. That was an inverted list of scientific references, where you could look up an scientific paper in an expensive set of bound books and find all the papers in which it was later referenced. You can then use this to see who's getting referenced a lot, which is an ego trip in academia. Academic libraries had copies of that index. Now everybody has that kind of info, but when it had to be done by hand, it was hard.
Inverting the huge, sparse matrix of references for PageRank was expensive. Originally, Google did it about once a week. The big breakthrough was when someone (who?) figured out how to do it incrementally at scale.
by Animats - Thinking of an algorithm in the abstract is one thing, implementing it at scale is another.
Yes you could have invented PageRank, but could you also have invented MapReduce, BigFiles/Google File System (GFS), Google Web Server, Bigtable, Protobuf? Then spun up fault-tolerant clusters consisting of cheap commodity PC hardware in an era where AWS wasn't even an idea yet? Then invented the concept of Borg to manage this hardware globally?
by paxys - Well, I was a child in 1996, so probably not.
Tying relevancy to link frequency was definitely a novel idea at the time, even if it seems "obvious" or simple in retrospect.
by smcg - Here are two excellent videos that explain and visualize the PageRank algorithm:
* [2020-06-17] Spanning Tree - "How Google's PageRank Algorithm Works" (5m16s): https://www.youtube.com/watch?v=meonLcN7LD4
* [2022-05-23] Reducible - "PageRank: A Trillion Dollar Algorithm" (25m25s): https://www.youtube.com/watch?v=JGQe4kiPnrU
by nayuki - PageRank is fascinating, since it is so easy to explain.
Yet, this is not even half the work. It like a third of the way.
Before you could have invented PageRank, you must think in graphs. That is possible in 1996, but not as widespread as today.
After you invented PageRank, you still need to deploy it. Again, possible but challenging as well. Is Python performant enough in 96? Can you afford more than 4MB RAM?
At least Lego will not sue you for using their bricks to build a server rack in 1996.
by ianbooker - I actually built this, and shipped it, in 1996, with no knowledge of page rank, citation analysis, or bibliometrics, for an internal/external search engine for the Envirolink web site. Envirolink was a directory of environmental web sites, so they already had a list of URLs to crawl. The reason it was feasible to build was that it was a fairly constrained list of URLs, it wasn't the entire web.
I didn't really know what I was doing (I was 17), but it was an awesome unpaid summer internship. There were two parts of the search engine - a crawler and the search engine. Both were written in Perl.
by jefflinwood