
Tabulation Hashing and Independence (2012) - Libertatea
http://rjlipton.wordpress.com/2012/04/14/tabulation-hashing-and-independence/
======
lutusp
This is the worst description of the randomness issue I have ever read. In
trying to make itself accessible to nontechnical people, it manages to miss or
misstate every key point about randomness and its uses. It also doesn't
understand the meaning or purpose of the function being described.

In the name of public accessibility, it's a perfect wash.

Guideline: if an article about random generating functions doesn't include the
word "entropy" in the first 1000 words, it's not worth reading.

~~~
nhaehnle
_Guideline: if an article about random generating functions doesn 't include
the word "entropy" in the first 1000 words, it's not worth reading._

I don't feel like that applies to the field "covered" by this particular
article, though. To give an example, one can write a useful and enlightening
article about the usefulness of randomness for universal hashing without ever
using the word "entropy". And it seems that hash functions is what this
article is trying to be about.

The article is a complete train wreck, but a lack of the word "entropy" is not
the cause.

~~~
lutusp
I would agree, except for the fact that the article claims the described
function produces a high degree of randomness -- "the most random function
ever" \-- which makes entropy an issue. If for no other reason, it would
reveal the author's familiarity with the field's terminology. Otherwise we're
entitled to assume that the hyperbolic claims have no basis (which I happen to
believe is the case).

I agree that the article ends up discussing hashing in a roundabout way, and
randomness seems to have been dropped as a topic, but the title cries out for
vindication.

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DanielStraight
Professor Thorup's papers are here:

[http://www.informatik.uni-
trier.de/~ley/pers/hd/t/Thorup:Mik...](http://www.informatik.uni-
trier.de/~ley/pers/hd/t/Thorup:Mikkel)

It would appear "Tabulation Hashing" is the key term. It's on Wikipedia here:

[https://en.wikipedia.org/wiki/Tabulation_hashing](https://en.wikipedia.org/wiki/Tabulation_hashing)

(EDIT: This comment originally appeared on a version of the story with a
different URL and different title, neither of which was particularly
informative.)

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trebor
Sounds like this is "the most random _hash_ function" rather than a random
number generator, as I first thought. I wonder how well it'll stand up to
scrutiny.

~~~
jordigh
Whenever I read mainstream news on topics I'm deeply familiar with, and I see
how badly they are reported, I realise that mainstream news probably
misreports all topics, not just the ones I'm familiar with.

~~~
lotsofmangos
I was thinking about this and wondering if it would be possible to have a news
organisation with no article writers, just editors who solicit articles and
interviews from domain experts.

~~~
trebor
It would be so different I'm sure that it has a chance to succeed, but it
wouldn't necessarily be easy to get started. I'm thinking mainly about the
difficulty in forming contacts, etc.

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bentoner
I think that this is the paper:
[https://scirate.com/arxiv/1311.3121](https://scirate.com/arxiv/1311.3121)

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dang
Can anyone suggest a better title? and more importantly, a better url? This
story might be interesting, but it's hard to tell from the article.

~~~
bentoner
This is a better article, but maybe it's too technical:
[http://rjlipton.wordpress.com/2012/04/14/tabulation-
hashing-...](http://rjlipton.wordpress.com/2012/04/14/tabulation-hashing-and-
independence/)

~~~
dang
Ok, we changed it. Thanks. The original url [1] was clearly not a good one for
HN.

1\. [http://sciencenordic.com/professor-revolutionises-
computers-...](http://sciencenordic.com/professor-revolutionises-computers-
most-random-function-ever)

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ultimatedelman
"But it will be the best for a great number of screws," he said, matter-of-
factly.

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gesman
How does randomness speeds up retrieval of data?

You may pick up random girl in a bar but if you like to retrieve her the next
day - you won't dial the random number, do you?

