My blog has moved!

You should be automatically redirected in 6 seconds. If not, visit
http://www.scienceforseo.com
and update your bookmarks.

Showing posts with label social networks. Show all posts
Showing posts with label social networks. Show all posts

January 30, 2009

Heat diffusion for Social net marketing

The paper we look at here is called "Mining Social Networks Using Heat Diffusion Processes for Marketing Candidates Selection" and is by Yang, Liu and King from The Chinese University of Hong kong.

Companies have started social networks more and more for WOM promotion, increase bran awareness, attract potential clients and so on.  This is openly apparent in Facebook pages, Twitter, collaborative filtering, blogs and many many others.  This paper presents a model enabling marketers to make the best use of these networks using the "Heat Diffusion Process" (which is an idea borrow from the field of physics).  They have 3 models and 3 algorithms to demonstrate that allow for marketing samples to be collected.

In physics the heat diffusion model states that heat flows from a position of high temperature to one of low temperature.  

They show that these methods allow us to select the best marketing candidates using the clustering properties of social networks, the planning of a marketing strategy sequentially in time, and they construct a model that can diffuse negative and positive comments about products and brands to simulate the complex discussions within social networks.  They want to use their work to help marketeers and companies to defend themselves against negative comments.  The idea is to get a subset of individuals to adopt a new product or service based on a potential network of customers. 

The heat diffusion model has a time dependant property which means that it can simulate product adoptions step by step.  The selection algorithms can represent the clustering coefficient of real social networks.  All users of social networks can diffuse comments that can influence other users. Based on this they say that nodes 1 and 2 represent adopters and the heat reaches nodes 3,4 and 5 as time elapses.  The users in the trust circle of other users have a greater influence.  Not all of the people in the trust circle however will be contacted about the heat source.  Also some users are more active than others in diffusing information.  they observe that bad news or negative comments diffuse much faster than other news.  

Individuals are selected as seed for heat diffusion.  The influence of individuals is based on the number of individuals they influence. The heat vector they construct decides on the amount of heat needed for each source.  In order for them to diffuse properly they need a lot of heat.  Thermal conductivity is then calculated.  It sets the heat diffusion rate.  The adoption threshold is then set, as if one consumers heat value is higher than others, they are likely to adopt this product.

If a user doesn't like the product, s/he is allocated negative heat as they will diffuse negative comments.  At some point someone in the network will provide different information which might be positive.  If that user adopts the product anyway, they will diffuse positive comments.  Two defense candidates are then selected and then the negative impact is alleviated.  

They conclude:

"So far, our work considers social network as a static network only, and ignores newcomers, new relationships between existing members and the growth of the network’s size. In the future, we plan to consider the evolution property of social networks, and permit our social network to grow at a certain rate"   

Why should you care?

This paper shows a new and very different way of analyzing social networks.  It gives you a nice opening ti discussions concerning this in a different light.  The current methods used in business are not foolproof and such research shows us how simplistic they are and how they can actually be misleading.

November 21, 2008

Issues with collaborative voting

Collaborative voting is used a lot these days in news systems, where people submit articles and others vote on whether they are interesting or not.  The articles with the most votes are ranked highest if you like, making it to the much coveted front page.

There are some issues with these systems which cause degradation in user feedback, here are a few:

  • Not all votes carry the same weight - if an expert votes on an article and a layman does, the expert vote is the most noteworthy.  There are problems with establishing who are the authorities on which topics.
  • Social voting: consistently voting for people you know and your friends.  These are not always votes based on the quality of the article.  
  • Sometimes though, users find that they appreciate articles from a certain author and track them, voting often on their submissions, but in this case, it is a genuine vote.  It's hard to tell these apart.
  • Some votes are generated without much thought.
  • Some votes are given for fun or for profit.
There is a lot of research going on to resolve these issues, take a look at these to start with:


"A Few Bad Votes Too Many?  Towards Robust Ranking in Social Media" (Jiang Bian, Yandong Liu, Eugene Agichtein, Hongyuan Zha)

"Dynamics of Collaborative Document Rating Systems" (Kristina Lerman)


November 19, 2008

Optimal Marketing Strategies over Social Networks

"Optimal Marketing Strategies over Social Networks" (www 2008) is a paper written by Jason Hartline (North-Western Uni), Vahab S. Mirrokni (MIT), Mukund Sundararajan (Stanford).  It's interesting because it gives an idea of how businesses can use social networks in an effective way to sell their products.  

I think the isse at the moment isn't selling products via SN but rather going in unintelligently with the hard sell, and the spamming.  The way to sell your products and services is to find interested individuals and to approach them in a friendly, social networking way, about your stuff.  Use social networking etiquette.

They looked at influence and revenue maximization.  The buyers descision to buy the product is influenced by other buyers in the social network and also by the price of your product.  When the buyers were completely symmetric, they could find the optimal marketing strategy in polynomial time.  

They looked at approximation algorithms and used the influence-and-exploit strategy.  Basically , you give the product for free to a select number of buyers, then you use a "greedy" pricing strategy for the buyers attracted by the influential individuals in their community.  They developed set-function maximization techniques to locate the target buyers to influence.  When other buyers are influenced from others, it's called "the externality of the transaction".  When there is a positive sale, it's called a "positive externality".

We know that users with the most connections have the most influence.  However the probability of people buying the product decreases as the marketing strategy progresses.    This is why the ultimate method is to give the product away to start with, much like Tivo did.  

To start with, you approach individuals and give the itme away, the you go on to the "exploit" stage. You visit buyers in a random sequence and offer them a "myopic price" (optimal pricing for revenue based on the influence of the initial buyers and the buyers who have already bought the item).    

They used a simple dynamic programming approach to identify an optimal marketing strategy.  Because it's symetric, the order in which you appraoch buyers is irrelevant.  "the offered prices are a function only of the number of buyers that have accepted and the number of buyers who have not, as yet, been considered."  

They found that the problem of computing the optimal strategy was NP-Hard, even when there was no uncertainty in the input parameters.    Using automated things to comoute strategies also involve computing issues such as this basically, you don't have to worry too much about that right now unless this stuff tickles your fancy.

The conclusion:

If a set S of buyers have previously bought, offer the next buyer i price vi(S). Buyer is i, Vi is the value of the buyer and S is a set. Vi(S) is a non-negative number.

This price simultaneously extracts the maximum revenue possible and ensures that the buyer buys and hence exerts influence on future buyers."

There is a lot more detail in the paper and the equations are worth a thousand words as always.  Take a look if you're interested in picking at it.

November 13, 2008

Sphinn spam - some solutions

*Before you read, a clarification - I'm aware that Sphinn is working on a newer version, and also that they use editors, mods and user interaction for spam fighting - this post is about those techniques and their limitations, and also introduces some new ideas*

Sphinn has been swamped with spam recently, I've seen a lot of it myself and it's been reported by other users, including Zigojacko.  What's up?

Although Sphinn is small in comparison to Digg, it uses the same kind of system.  People submit stories and they get voted by other members.  The posts with the most votes go to the "Hot topics" page, which is also the content that you'll get in your feed.  Basically, it's the same thing.  People post advertising for their products and services instead of information rich resources that can be shared with the community.  It's also a drain on resources.  All in all, a nasty thing that needs to be dealt with.

Ways that this problem can be solved include:
  • Having a human spam editor 
  • Getting users to flag spam 
  • Moderation 
  • Captcha (not effective for human submissions)
  • Relevance rank
  • and finally...personalisation.
Having a human spam editor isn't ideal in a very dynamic environment like Sphinn.  It works for Wikipedia, but it moves at a much slower pace.  Captcha is only useful for deterring bots (although some can break captcha now).  Moderation uses human resources and is time consuming, Tamar and Danny at Sphinn make it clear in the Zigojacko thread.  Moderators should not have to clear out the spam anyway.  That leaves...

Personalization:
Digg already announced at Web 2.0 expo that they were working on a personalised front page.  This means that, yes, you might still get spam on your front page, but it's not really going to be worthwhile for the spammers, seeing as their audience becomes very small all of a sudden.  You get to moderate your own "front page", and in this sense, I guess something like Twine is worth a look (I really like Twine btw).

There is a way for spammers to use this to their advantage though, and this would be through social network monitoring, to detect where their interest group is, and then target them in some way, like with paid for ads.  It is still tricky though.

Relevance rank:
Most people will be aware of this, it's basically ranking results by relevance, but first you have to decide what's relevant.  

On Sphinn, new submissions come in on the "what's new" section as they are submitted, which I like.  Sometimes stuff I'm interested in doesn't get many votes and they'd be buried before I could come across them (not "find" - I'm never looking on Sphinn, I'm browsing).  This section is easily spammed and to be honest it's not as bad as I've seen it elsewhere.  

There has to be a filter as stories come in to minimise spam at this level.  One way to do it would be to use a topic detection algorithm and train it on a clean already existing Sphinn corpus.  The system can draw patterns from the training data which help it label a submission with "Sphinn" or "Foe".   The patterns will be numerous!  A cool by-product is a way to visualize the community.  

This type of method needs to be flexible as well though, otherwise if you used an unconventional title for example, or weird words, your submission would be chucked out.  The more you train it the better it gets and I would define Sphinn as a closed environment, which makes the problem easier to deal with.  There are only so many categories.  It's not as difficult as tracking spam in a global engine.  On top of that you could take into consideration user interaction to solidify your method.

Or failing all of that, we could beg: "Spammers, please please stop  peeing in the beer".

November 12, 2008

Social network analysis tool

Agna (Applied Graph & Network Analysis) is a tool built for social network analysis, sociometry and sequential analysis.  With Agna you can study relationships between groups, relationships between people, and the structure of social networks.  The results are graphed nicely so that you can simply see the results of your analysis.

It uses network analysis which assumes that the way that people communicate affects important properties of that group.  Here nodes are people and edges are communication acts.  It also uses sequential analysis which identifies the constants and rules that govern the inner structure.  

It was developed by Marius I. Benta, a PhD student at University College Cork (Ireland). 

It's a free download (windows, Mac, Linux), and you can see more  screenshots here.


November 09, 2008

The profile picture

We belong to at least one social network, and it requires you to have a profile picture.  How do you choose?  If you belong to lots of social networks do you use a different one in each?

PhD comic suggests:

October 20, 2008

SISN toolkit for social media


 Kicking off the week with a technical poster from Michigan University called "SISN: A Toolkit for Augmenting Expertise Sharing via Social Networks".  

They're developing a toolkit to support expertise sharing via social networks.  The toolkit "SISN" (Seeking Information via Social Networks) is "is a general purpose toolkit for social network-based information sharing applications that combines techniques in information retrieval, social network, and peer-to-peer system".

Their toolkit requires:

• A collection of users with their expertise being represented by their profiles
• A social network that connects the users and place them along the query/referral/answer pipeline
• A collection of searching strategies to spread the query/referral efficiently across different user groups
• A coupling of the system with daily communication channels (e.g. IM and
Email) to provide a convenient interface between the major parties involved in the information seeking process

The system consists of:
  • Information profiling
  • An index
  • Categorizer
  • Social network module
  • Social network module
  • Profile Promoter and Peer Profile Learner
 They say that there is a gap between the search for information on social networks and the advent of the web and Internet in this information era:

"We believe that, by providing a general-purpose toolkit as a platform for sharing and seeking expertise via social networks, the current work helps us advance towards narrowing the gap between the social and technical perspectives of social network-based information seeking, i.e. the gap “between what we have to do socially and what computer science as a field knows how to do technically”.

I think that this would lead to a whole new rush to optimise yourself so that you show up in the experts for your chosen subject area.  

Unfortunately as far as I can tell they haven't made it freely available to us as yet which is a shame, but I'll watch that space.
Creative Commons License
Science for SEO by Marie-Claire Jenkins is licensed under a Creative Commons Attribution-Non-Commercial-No Derivative Works 2.0 UK: England & Wales License.
Based on a work at scienceforseo.blogspot.com.