Posts Tagged ‘postgresql’

TunkRank Improvements

Posted: 17 February 2010 in Uncategorized
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Over the past few weeks, I’ve been working on a number of improvements to TunkRank that I will be rolling out tonight. First, I’ve secured a server to host it on, rather than my old Dell laptop, so reliability should improve and TunkRank is no longer a slave to dynamic DNS problems. Also, my cable company is less likely to hunt me down. TunkRank has gotten some increased attention over the past few weeks, including from Chris Dixon, CEO of the wonderful website hunch:

Twitter could fix the whole follower obsession by highlighting a more meaningful metric like TunkRank.

Awesome! So with this new version, there are a few changes that will immediately impact you, the end-user. I’ll go into the ones that affect you the most first, followed by some technical points of interest for those who care. Then I’ll conclude with a couple of hints at the future.

Changes to TunkRank

First and foremost, I have changed the main score that is reported. Previously I was using a percentile in the range (1-100). This got a lot of objections and created confusion. Partially because I consider the 100th percentile to be the “top-tier” of users, while standardized testing often reports the 99th percentile to mean you performed better than 99% of the population. Also, most people who actually care about their scores enough to use TunkRank are in the 95-100 percentile range, making more fine-grained comparisons difficult. Neal Richter even posted on his blog some suggestions for improving it (quite a while ago, now).

I took a page out of Neal’s book with the log scores, but I also put it in a range where the most influential twitter user (let’s call her MAX) will always have a score of 100. Your TunkRank Score™ is the ratio of the log of your raw score to the log of MAX’s score. So formulas aside, this means your TunkRank score is directly comparable to other users and is always in perspective of the maximum influence exerted by any user in the Twitterverse. Incidentally, comparing users with a difference of seven TunkRank score points means the user with the higher score is about twice as influential.

Accessing the API has also changed slightly, and I apologize to anyone actually using it at the moment. Basically, I am matching the API calls to more closely conform to the URLs used on the web side, and I’m returning more information with each call. TunkRank also supports XML responses in addition to JSON. You can find all of the documentation here.

Some Technical Notes

As part of the move, I’ve decided to transition from using Merb to Rails. My original decision to use Merb was partially as a learning exercise, but also because Merb appealed to me with its being lightweight. However, I often ran into roadblocks because some useful plugin wasn’t supported (or I couldn’t figure out how to make it work in the limited time I had). Sometimes the documentation for Merb was very good and sometimes it was absent altogether. Rails, on the other hand, has a substantial amount of documentation and people are always blogging about the best way to do things — which makes life as a developer much easier. Rails is my day job, so I knew I could transition quickly and easily.

I also migrated from MySQL to PostgreSQL. The main reason is that I love PostgreSQL — plain and simple. They both have their advantages, but MySQL gives me a sense of uneasiness I don’t have with PostgreSQL. I’ve managed to achieve some nice speed improvements as part of the redesign, though that is not to say that the same speed improvements wouldn’t have been possible with MySQL.

I’ve also adopted Resque as my background job-processing library. It is backed by Redis, an advanced key-value store that you can think of as a “data structures server.” The important thing for me is that Resque is fast, has a kick-ass web interface, and integrating with Rails is brain-dead easy.

The Road Ahead

I wrote before about the road ahead for TunkRank, and I have mostly held to it. I have many more ideas I want to expand on, including topic-sensitive influence rankings. I like the ideas in the recent WSDM paper (pdf) by Weng et al, but I have a few new ideas I’m eager to try out. TunkRank scores may also be integrated into Tickery in the near future, thanks to some discussions with Terry Jones of FluidDB.  I’m excited!

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