Saturday, April 16, 2011

What does it take to be a data scientist?

Conway on what it takes to be a data scientist (@ ZIA, ht: Mike B).


The full article is here. It's short and sweet, and offers a nice counterpoint to some of the claims made by people with a more computer-science-centric view of the world. Turns out that modeling assumptions (i.e. math and statistics) and theory (i.e. substantive expertise) matter. You ignore them at your own risk.

PS: The title makes it sound like this is about U.S. intelligence, but almost all the points in the article apply to business and academia as well.

Friday, April 15, 2011

More text archives

Three more data sets (108MB, gzipped) for training classifiers. All these files are text-only, crawled in the week of 12/17/2010. It just took me a while to get around to releasing them.
political (115M):
Front pages from ~2,500 political sites. These sites were rated extremely likely to be political (p>.99) in an early version of my census of the political web. I revisited the same sites several months later and downloaded the new front pages to create this dataset. They should be appropriate for case-control training of a political classifier.

random (471M):
Front pages from ~8,000 "random" sites. These are a pseudo-representative sample of the web. I ran several web spiders in parallel, recording all outbound links from visited sites. I deliberately undersampled common namespaces, in order to avoid getting trapped in densely-linked social networking sites. The 8,000 sites are a random sample from a list of ~2 million sites generated in a crawl of this type.

porn (43M):
Front pages from ~1,200 pornography sites. I never thought I'd be curating pornography as part of my dissertation, but so much of the web is porn that I've had to build special classifiers to screen it out before sending to my undergrad research team for coding. These 1,200 sites were all linked from http://research.vision-options.com/research.php.

Thursday, April 14, 2011

It's data dump week!

In case this wasn't clear already, it's data dump week. I'm gearing up for another crawl of the political web, and posting lots of bits of code and data along the way. If nothing else, I'll be able to find them here in the future. If these (or similar) resources are useful to you, please let me know.

Cheers!

Data release: 75K political web sites

Data release:
pol_site_sample.tar.gz (1.2GB, gzipped)
This archive contains results from a front-page-only crawl of ~75,000 political web sites on 4/9/2011.

These sites span a large portion of the political web, but they are not a representative sample. Each was classified as very likely to be political (p > 0.9) in a crawl performed in August 2010. In other words, these are pages from sites that featured political content 8 months ago. Presumably, most -- but certainly not all -- of the sites still feature political content today.
I'm going to use this to train content classifiers. Might be useful to others as well.