My attempt at showing a working model for stumbleupon mathematics certainly got (is getting) a lot of attention with several questions being asked I thought I would at least try to answer some of them and pass some more generic comments.
If you haven’t read the stumbleupon mathematics post then this will not make much sense but to recap the proposed “simplistic big model”
(Initial stumbler audience /# domain) + ((% stumbler audience /# domain)+ organic bonus – nonfriend) – (((% stumbler audience + organic bonus) + N
http://ventureskills.wordpress.com/2007/09/19/stumbleupon-mathematics-for-stumblers/
So now on to the questions.
1. You said this was a simplistic model how many variables do you think there are?
Tim - Far more then 6 in the proposed “big model” our full big model included 20 variables but this was a restriction of the data rather then the model.
2. When you say modelled have you simulated and if so how accurate was it?
Tim - Yes I have run computer simulations with mixed success we never simulated a large stumble with the exact same number of visits. We also did not use N a random variable rather substituting it for an error margin.
3. What language did you model it and when it being released?
Tim - The model was simulated with Python and I have no intention of releasing the full formula I used or the script in any form sorry.
4. Why not?
Tim - The model is not accurate its close (in predicting historical stumbles) but its not accurate, if I’m close then the guys at stumbleupon may change the algorithm I do not want my name to be a swear word for Ebay engineers for years on end. If I’m not close well I have a pride thing at stake plus I did it to satisfy my curiosity it was never meant to be heavily scrutinised.
5. But you can predict how well a sumble will do?
Tim - Nope we can simulate how well a stumble did we require historical data to simulate, I have no idea who will stumble a post and therefore can’t possibly predict how it will react.
5. But you have a shrewd idea of Audience scores?
Tim - Again yes and no, I sadly didn’t pay attention to the audience scores when they were published so have had to go on a lot of guess work. I can with some success tell you the rough percentage difference in audience scores of 2 stumblers given enough data. Mind you by the time I have worked it out you could have just looked at their profiles and told me the answer with as much accuracy!
6. What effect is a thumb down do?
Tim - This was hard to collect data we did run some small tests, but obviously we didn’t want to pollute stumbleupon with tests so had to keep such things small scale and mark them down as spam ourselves, I’m not sure what the engineers who received the spam report thought
It does however have an effect and is determined by audience score.
7. Does thumbs down count towards increasing Audience score?
Tim - Pass, I modelled both my gut says no, but I have no evidence to support that.
8. Are you really sad enough to simulate some one else’s algorithm and then not even release it?
Tim - hmm yes!
9. How can I game the system?
Tim - I wish I could say you can’t but that would be untrue but the best way to game stumbleupon is to use it or get people to use it on your behalf. Remember each failed attempt counts against you.
10. Can you game the system?
Tim - no more so then anybody who has played with stumbleupon for some time.
11. If I give you a vast quantity of money will you game stumbleupon for me?
Tim - You can give me the money but as stated above I’m not in a position to game the system, but my company does provide Social media optimisation services so get in touch (sorry blatent plug it was a question asked though!)
12. You pretty sure mailing lists don’t work but I know they do?
Tim - cool what floats your boat, I didn’t say they don’t work I said they loose their effect if repeatedly used on the same domain.
13. Did you know your really sad?
Tim - yes, but geeky so that’s ok.
14. So do you know how Page rank works?
Tim - Sure here’s the patent moving on please, to the best of my knowledge Stumbleupon or ebay have not applied for a patent on the stumble algorithm I may be wrong and would love to see it if they have.
Hope that covers some of the questions you might have had if not please leave me a comment and I will try to answer it.
More Stumbleupon content from Tim
Stumbling research
- Stumbleupon mathematics for stumblers
- What do I & top stumblers have in common
- Organic Stumbling tip
Stumbleupon vs Digg
- Page Layouts
- Voyeurs vs Sheep
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September 21, 2007 at 10:58 am
[...] More questions then answers « The Venture Skills Blog Says: September 21st, 2007 at 10:56 am [...]
September 23, 2007 at 4:20 am
I want to let you know how much I appreciate your research.
It does explain what I saw when I stopped submitting my own domain with any regularity, and instead focused on submitting lots of other sites (thanks to my Delicious Stumbles).
When I do submit my own site now (very infrequently) it typically does well — unless I use the “send to” feature that just kills it.
September 23, 2007 at 8:33 am
Thanks Engtech
Its interesting that stumbleupon introduced lots of features that make its toolbar very easy to use, but also leave the system open to abuse. I suspect even as late as June the send to acted organically and would have as much stumble juice as a random visitor from the toolbar. But spammers quickly worked out how to abuse it so the engineers had no real choice devalue the click or remove the feature.
September 27, 2007 at 12:51 pm
[...] To test stumbleupon algorithm [...]
September 29, 2007 at 9:37 pm
[...] To test stumbleupon algorithm [...]
October 2, 2007 at 3:12 pm
Hard…. to test stumbleupon algorithm
December 12, 2007 at 10:59 pm
Very interesting piece.
What are the effects of the ‘Useful Yes/No?’ option next to reviews? I’ve always wondered about that.
December 13, 2007 at 9:24 am
@Nate I think this may have been answered on the previous post but from all the bits we did it had no impact at all the “is this review helpful” seems to be part of Stumbleupon customer services tool for tracking spam and or malicious comments.
April 10, 2008 at 5:43 pm
I found both your breakdown of the algorithm, and your answers to be interesting. I am also a bit of a geek (self confessed and proud) and always like to find out how things work. Not simply in order to abuse it, but just for a level of understanding. Lots of people use computers without knowing how they work. That is totally fine, but I like to know how they work, so I can use it better.
I think your breakdown just proves that in order to use stumbleupon to the greatest effect, you need to be a good honest stumbler, so hats off to the stumbleupon engineers for creating it.
eg. thumbing up sites you like; looking around and discovering sites you like and you think others will like; being part of the stumble upon community and making friends.
All these are not only positive in the way of building stumble cred, but also part of being a good honest, nice stumbler. If you go around discovering crap for the sake of it, and thumbing up any old tripe, it won’t work. It’s about finding quality among the already filthy sea of the internet, and the stumbleupon people reward you for that, and rightly so.
So in the end, someones method of trying to cheat stumble by figuring out their code, and working towards it is in a sense making themselves into a good web surfer and stumbler. A bit like trying to cheat in a test by hiding the answers in your head.
I enjoyed this
April 10, 2008 at 5:43 pm
P.S. Yea I know I’m like 4 months late for the above comment, but thought I would add my 2pence anyway.