Friday, September 08, 2006
Digg Algorithm For Scoring StoriesHere is a condensed version of what Kevin Rose & Jay Adelson confirmed as being some of the core elements used in determining the ranking (could substitute relevance here) for a story on digg. Again, these are my personal notes from our meeting with them and hopefully this will make it fairly clear what parts the "machine" looks for on new stories and user diggs. Also, if you know anything about seo, then all of this will sound a bit familiar. Digg is now where Google was circa 1999.
Digg Scoring Elements
1.) Not a set number of diggs in order for a story to be promoted.
2.) Brand new users are like automatic penalties in the search engines (sandbox effect).
- I asked Kevin if they were going to call this part of their algorithm diggbrother, that got a good laugh out of everyone that was on the call.
3.) Buries are often overlooked but are key to their ranking
3a.) Buries are not boolean in value. Digg looks at...
- Number of people that buried it before it was promoted
- What is the audience like (history, tendancies, etc...) that diggs / buries the story
4.) The time of day the story was submitted is included in the ranking algorithm.
Because people watch the digg spy, labs, etc...
5.) Digg crawls the stories that are submitted to look for additional content such as images,external links, etc...
6.) The person submitting a story is not factored in when ranking a submission.
7.) URLs are all treated equal - no preference to the mainstream.
- exception: if url has been banned. They were emphatic about this point and said they know they aren't perfect and that some good urls got banned on accident but they're more than willing to manually correct those.
- if reported by enough users
- fraudulent url, spam site, etc...
8.) Reputation plays a role. A positive reputation means...
- If you agree with the same person over and over again it's a red flag (think automatic penalties in Google & Yahoo)
- Agreeing with a friend is not a behaviour they want to penalize but if the same 20 people digg the same stories together as if they are one mind they must be treated as one mind. Definitely a clever one-liner Jay has had to use many times in the past for sure.
- Karma DOES impact promotion (as they have said in the past).
9.) The lifeline of a story is monitored as well.
- who diggs the story and the sequence of those diggs (is it the same people digging the stories?)
10.) Age of users is a conundrum
- Readers Digest Version: It doesn't take a year to gain a good reputation
11.) They will not show who buried stories in rss feeds because they don't want to start flamewars by showing people that are burying stories.
12.) They receive 4,000 - 5,000 stories submitted a day and it's impossible to handle that kind of volume without having sophisticated algorithms running on the backend. Ultimately, they stood by their statement that Digg is all about the wisdom of the masses.
Jay "A submission is equal weight"
By Jason Dowdell at 08:47 AM | Comments (8)