OUseful.Info, the blog…

Following on from Social Networks on Delicious, here’s a view over my delicious network (that is, the folk I “follow” on delicious) and the dominant tags they use:

The image is created from a source file generated by:

1) grabbing the list of folk in my delicious network;
2) grabbing the tags each of them uses;
3) generating a bipartite network specification graph containing user and edge nodes, with weighted links corresponding to the number of times a user has used a particular tag (i.e. the number of bookmarks they have bookmarked using that tag).

Because the original graph is a large, sparse one (many users define lots of tags but only use them rarely), I filtered the output view to show only those tags that have been used more than 150 times each by any particular user, based on the weight of each edge (remember, the edge weight describes the number of times a used has used a particular tag). (So if every user had used the same tag up to but not more 149 times each, it wouldn’t be displayed). The tag nodes are sized according to the number of users who have used the tag 150 or more times.

I also had a go at colouring the nodes to identify tags used heavily by a single user, compared to tags heavily used by several members of my network.

Here’s the Python code:

import urllib, simplejson

def getDeliciousUserNetwork(user,network):
  url='http://feeds.delicious.com/v2/json/networkmembers/'+user
  data = simplejson.load(urllib.urlopen(url))
  for u in data:
    network.append(u['user'])
    #time also available: u['dt']
  #print network
  return network

def getDeliciousTagsByUser(user):
  tags={}
  url='http://feeds.delicious.com/v2/json/tags/'+user
  data = simplejson.load(urllib.urlopen(url))
  for tag in data:
    tags[tag]=data[tag]
  return tags

def printDeliciousTagsByNetwork(user,minVal=2):
  f=openTimestampedFile('delicious-socialNetwork','network-tags-' + user+'.gdf')
  f.write(gephiCoreGDFNodeHeader(typ='delicious')+'\n')
 
  network=[]
  network=getDeliciousUserNetwork(user,network)

  for user in network:
    f.write(user+','+user+',user\n')
  f.write('edgedef> user1 VARCHAR,user2 VARCHAR,weight DOUBLE\n')
  for user in network:
    tags={}
    tags=getDeliciousTagsByUser(user)
    for tag in tags:
      if tags[tag]>=minVal:
         f.write(user+',"'+tag.encode('ascii','ignore') + '",'+str(tags[tag])+'\n')
  f.close()

Looking at the network, it’s possible to see which members of my network are heavy users of a particular tag, and furthermore, which tags are heavily used by more than one member of my network. The question now is: to what extent might this information help me identify whether or not I am following people who are likely to turn up resources that are in my interest area, by virtue of the tags used by the members of my network.

Picking up on the previous post on Social Networks on Delicious, might it be worth looking at the tags used heavily by my followers to see what subject areas they are interested in, and potentially the topic area(s) in which they see me as acting as a resource investigator?