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Alexandria Search

alexandria.org

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Re: Alexandria Search

#111

Hello, My name is Josef Cullhed. I am the programmer of alexandria.org and one of two founders. We want to build an open source and non profit search engine and right now we are developing in our spare time and are funding the servers ourselves. We are indexing commoncrawl and the search engine is in a really early stage. We would be super happy to find more developers who want to help us.

The UI is amazing. Don't change it significantly!

Re: Alexandria Search

#112

Earlier quoted context omitted.

I was trying to learn more about the ranking algorithm that Alexandria uses, and I was a bit confused by the documentation on Github for it. Would I be correct in that it uses "Harmonic Centrality" ( http://vigna.di.unimi.it/ftp/papers/AxiomsForCentrality.pdf ) at least for part of the algorithm?

Hi, Yes our documentation is probably pretty confusing. It works like this, the base score for all URLs to a specific domain is the harmonic centrality (hc). Then we have two indexes, one with URLs and one with links (we index the link text). Then we first make a search on the links, then on the URLs. We then update the score of the urls based on the links with this formula: domain_score = expm1(5 * link.m_score) + 0…

The main scoring function seems to be index_builder::calculate_score_for_record() in line 296 of https://github.com/alexandria-org/alexandria/blob/main/src/i..., and it mentions support for BM25 (Spärck Jones, Walker and Robertson, 1976) and TFIDF (Spärck Jones, 1972) term weighting, pointing to the respective Wikipedia pages.

Re: Alexandria Search

#113
post #111

Hello, My name is Josef Cullhed. I am the programmer of alexandria.org and one of two founders. We want to build an open source and non profit search engine and right now we are developing in our spare time and are funding the servers ourselves. We are indexing commoncrawl and the search engine is in a really early stage. We would be super happy to find more developers who want to help us.

The UI is amazing. Don't change it significantly!

[deleted]

Re: Alexandria Search

#114

Earlier quoted context omitted.

Yes it would be impossible to keep the index in RAM. >> It's hard for me to see how that could be done much faster unless you find a way to parallelize the process We actually parallelize the process. We do it by separating the URLs to three different servers and indexing them separately. Then we just make the searches on all three servers and merges the result URLs. >> I haven't read your code yet, obviously, but co…

We are currently just doing an intersection and then we make a lookup in a forward index to get the urls, titles and snippets. I actually don't know what roaring bitmaps are, please enlighten me :)

If you are solely supporting union or solely supporting intersection then roaring bitmaps is probably not a perfect solution to any of your problems.

There are some algorithms that have been optimized for intersect, union, remove (OR, AND, NOT) that work extremely well for sorted lists but the problem is usually: how to efficiently sort the lists that you wish to perform boolean operations on, so that you can then apply the roaring bitmap algorithms on them.

https://roaringbitmap.org/

Re: Alexandria Search

#115

Hello, My name is Josef Cullhed. I am the programmer of alexandria.org and one of two founders. We want to build an open source and non profit search engine and right now we are developing in our spare time and are funding the servers ourselves. We are indexing commoncrawl and the search engine is in a really early stage. We would be super happy to find more developers who want to help us.

What will be the USP that makes it a success we are all waiting for? At the moment I'm switching between DDG & Google.

Re: Alexandria Search

#116
post #112

Earlier quoted context omitted.

Hi, Yes our documentation is probably pretty confusing. It works like this, the base score for all URLs to a specific domain is the harmonic centrality (hc). Then we have two indexes, one with URLs and one with links (we index the link text). Then we first make a search on the links, then on the URLs. We then update the score of the urls based on the links with this formula: domain_score = expm1(5 * link.m_score) + 0…

The main scoring function seems to be index_builder ::calculate_score_for_record() in line 296 of https://github.com/alexandria-org/alexandria/blob/main/src/i... , and it mentions support for BM25 (Spärck Jones, Walker and Robertson, 1976) and TFIDF (Spärck Jones, 1972) term weighting, pointing to the respective Wikipedia pages.

This is actually not used yet. Working on implementing that as a factor.

Re: Alexandria Search

#117
post #33

There have been a few search engines out recently. I'm curious how people evaluate them quickly. I've realized my searching is basically optimized for google and the web that has grown up around it. Also, in 1998 I wasn't as aware of what was out there as I am now. It's pretty rare (even if its possible) that I do a search and come across a completely new site that I haven't heard of before, for anything nontrivial.…

> because they are optimizing for the current state of the web. I believe people will at least start looking for alternatives. For example, I have been collecting search engines, and whenever I encounter a page with too many commercial-laden SEO-porked results, I use a different search engine in Firefox. I have enabled the Search Bar, I can do Alt+D, Tab, Tab, enter my query, then click a different search engine, whi…

Pro tip: Alt+E takes you directly to the search bar, then you can press Tab for selecting the search engine. The best part is that you never use the mouse this way. You can also use ddg bangs, they contain every search-engine/site by pressing Alt-D if you remember the bang for the site.

Re: Alexandria Search

#118

There have been a few search engines out recently. I'm curious how people evaluate them quickly. I've realized my searching is basically optimized for google and the web that has grown up around it. Also, in 1998 I wasn't as aware of what was out there as I am now. It's pretty rare (even if its possible) that I do a search and come across a completely new site that I haven't heard of before, for anything nontrivial.…

I'm surprised you are not a fan of geeksforgeeks. While each of their webpages have substantially less content than the pytorch docs or SO result, I find that they get to the point instantly. My mean time to solution from G4G is definitely smaller than SO.

I guess everyone has their go-to sites and their pet peeves. Geeksforgeeks may be less spammy than some, but I still think of it as that annoying site that got in the way of either the SO or documentation answer that I was looking for.

Just to expand, if I want the api reference, say I search for defaultdict (for some reason I like using them but always have to look at the reference), I want the python documentation. I definitely don't want a third party telling me about it.

And if I search a "make list of tensor into tensor" type question, I want SO where someone had asked the same question and got "tensor.stack" as the reply, so I can understand the answer and follow up by looking at the tensor.stack pytorch reference it I want.

Anything else is wasting my time, I think most users with similarly specific queries are not looking for tutorials, they are looking for the names of functions they hypothesize exist, or references. That's why intermediary sites that try to give an explanation are annoying, at least for me.

Re: Alexandria Search

#119

Hello, My name is Josef Cullhed. I am the programmer of alexandria.org and one of two founders. We want to build an open source and non profit search engine and right now we are developing in our spare time and are funding the servers ourselves. We are indexing commoncrawl and the search engine is in a really early stage. We would be super happy to find more developers who want to help us.

What will be the USP that makes it a success we are all waiting for? At the moment I'm switching between DDG & Google.

I just think that the timing is right. I think we are in a spot in time where it does not cost billions of dollars to build a search engine like it did 20 years ago. The relevant parts of the internet is probably shrinking and Moore's Law is making computing exponentially cheaper so there has to be an inflection point somewhere.

We hope we can become a useful search engine powered by open source and donations instead of ads.

Re: Alexandria Search

#120
post #82

Earlier quoted context omitted.

I've been wondering for a while now about building a search engine for the ad free web. That is, penalize or outright refuse to index any recognized advertising network, letting through only those sites which don't perform invasive tracking with third party services. Mostly as a curiosity: what would be left? What would rise to the top when you filter all of that out?

Wikipedia.

Evidently someone disagrees, but no ads or trackers except on the home page and its pages rank highly on current search engines, so if you exclude trackers and ads that's what you're going to get.
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