Social Networking by yaohongm


									                 Social Networking
• Social networking has existed for as long as
  humanity has been drawn together into
  – We think of social network today as on-line
    communities but the study of social networking points
    out that such communities can exist in many ways
     • Communities of faculty and students in the classroom
     • Urban/Suburban communities (i.e., neighborhoods)
          – and as a variant, the communities formed in apartment buildings or
            apartment complexes
     •   Work-related groupings
     •   Communities created through co-ops, travel abroad
     •   Teams in sports
     •   Swingers parties (spouse swapping)
    Social Networking as a Science
• Social networking has been researched since the late
  – Social network analysis first started by Durkheim and
    Tonnies who were interested in identifying the factors that
    linked people together
  – Today, much of social network analysis is studied in a wide
    variety of disciplines
     • anthropology, biology, communications, economics, geography,
       information science, psychology, sociology and sociolinguistics
     • studies include how social networks function, network theory to
       model relationships, how one network can impact another or how
       one individual can impact a network, the sociological, political and
       economic impacts of a network and the different types of networks
       that exist
• The idea of 6 degrees of separation was coined by
  studying social networks
                   Network Theory
• A network is a collection of nodes and edges
  – A node represents an entity in the network
     • in this case, a person
  – An edge represents a relationship between two nodes
     • in a social network, an edge means a friendship or point of
       contact – two people communicate with each other
     • we could have different types of edges based on how the two
       people are connected: Relatives, Friends, Coworkers,
• A network (also called a graph) is dense if most
  nodes have edges to most other nodes and is sparse if
  the number of edges is small
  – If every node in a network has an edge to every other node
    in the network, then the network is called complete and
    will have (n-1)2 edges
  – A network is dense if the number of edges is close to (n-
    1)2 and sparse if the number of edges is close to n
      Measures of a Social Network
• Betweenness
   – how connected a specific node is to other nodes
• Bridge
   – a node which, if removed, causes two portions of the network to
     become disconnected
• Centrality
   – the rough social power of a node based on how well it is connected
     (a combination of betweenness, closeness and degree)
• Clique
   – a subset of nodes that all connect to each other (a complete
• Closeness
   – how many links on average exist between this node and all other
     nodes (if a node can reach any other node in just a few links it is
     considered to have high closeness)
• Cohesion
   – groupings of nodes that are directly connected to each other
• Degree
   – the number of edges connected to this node
• Directed graph
   – a graph in which edges have a direction, that is, if the edge goes from
     Node A to Node B, then you can only travel in that one direction
• Local bridge
   – an edge that connects nodes who have no common neighbors
     between them
• Path length
   – the distance between a pair of nodes
   – the average path length is the average of the path length of every pair
     of nodes
• Prestige
   – in a directed graph, this term indicates a node which is the end point
     of many edges (many edges point to it)
• Structural cohesion
   – The minimum number of nodes that, if removed, would disconnect
     the graph
    Social Networking on the Web
• The term social network has become popularized
  because of communities that have grown out of
  Internet contact
  – Today, the number of such communities has grown and
    the number of members of such a community has
    surpassed all previous sized social networks
• Most social networks on the Internet are web based
  – You interact with other members by going to a common
    web site
     • Posting/discussion boards and blogs
     • Your own web pages
     • Email list serves (emails that go to everyone in the group)
  – List serves do not need to be based on web sites but it is
    the more common approach today because its easier to
            Popular Social Networks
• Facebook
   – over 500 million people, each has their own page(s) and can upload
     messages, images, other files, and link to others known as “friends”
   – recently Facebook has been blocked in several countries to
     discouarge employees from wasting time on it and/or to limit
     exposure to outside ideas
• MySpace
   – older than Facebook and was originally more popular until 2008,
     now it is the second most popular of the social networking sites
   – having your own myspace site requires that you create an account,
     but unlike Facebook, you can view other people’s sites without an
• Twitter
   – unlike the other two, Twitter is mainly an avenue for short blogging
     – a user sends out tweets to those who have subscribed to his/her
     friends list
   – its commonly used so that celebrities can send short messages to
     their fans whenever they feel like it
                        Other Sites
• LinkedIn
   – more for business people, it allows someone to maintain a list
     of contacts of people they know and trust
   – people can meet people through their lists (for instance, if
     person A has a list that includes person B and person B has a
     list that includes person C, then A can meet C
   – through contacts you can find jobs and employers can seek out
• Bebo (Blog Early Blog Often)
   – as the name suggests, this site is mostly for users to have their
     own blog space but it combines features like friends from
     FaceBook so that you can blog to certain communities
   – also features Bebo Music so that musicians can get their music
     out into the public
• Friendster
   – created by two guys in California (prior to the creation of
     FaceBook or MySpace), it is similar but has become much
     more popular in Asia and not popular in the US
 Earlier Forms of Social Networking
• Listserv
   – offers email lists – sign up for a particular list and anyone on that list
     can send an email to the entire list
• Usenet
   – an early form for blogging, Usenet offers electronic bulletin boards,
     each of a specific topic (e.g., or
   – there are about 100,000 different bulletin boards (topics)
   – was first made available in the 1980 and is still somewhat popular
   – like a discussion board on a web site but if you subscribe to usenet,
     you get access to all of the discussion boards
• IRC (chat)
   – a real-time version of the electronic bulletin boards
• Prodigy/AOL/CompuServe
   – these early wide area pay-for-access networks offered many of the
     features we now see – email lists, bulletin boards, sites to post
     information, etc
                      Social Network the scope of
     Building asocial network is well beyondWebsite
    Creating your own
  this course
• But what would it involve?
    – It depends on what features you want to offer
• At a minimum
    – A database to store member info (names, email addresses, usernames,
    – A secure connection for people to log in
        • use https for secure communication
        • involves running an authentication (login) program
        • the web server has to be set up for this
    – A privacy policy since you are obtaining people’s personal information
• Now what?
    – Discussion/posting boards? This requires forms for input and a
      database to store all of the threads and postings
    – Email lists? This requires a listserv
    – Web space? This requires that people have the ability to upload their
      content (probably through a form rather than using FTP)
    – Multimedia? The ability to store and play multimedia
        Value of Social Networking
• Allows people to make friends they would not ordinarily
  have access to (because of distance or other factors)
• Allows people to learn of other societies, communities,
  customs, etc
• Convenient way to communicate en masse
   – it also shelters people from having to communicate in person
     or in groups in case you are not a good public speaker or do
     not have good social skills
• Gives people an outlet for their thoughts
• Can potentially save resources
   – if you can “talk” to friends on-line then you don’t necessarily
     have to get in your car and use gas to “see” them
• Provides a means for advertising
   – musicians and artists often use FaceBook or MySpace to post
• Can give people a feeling of satisfaction in that they have
  more “friends”
 Relationships, Weddings and Donors?
• You probably know someone who met their
  boyfriend/girlfriend/spouse through a social
  – Good thing? Probably
  – On-line dating lets you
     • find a close match
     • avoid the hassle of doing the “singles’ scene”
     • evaluate a person without meeting them
  – And there have been a lot of success stories – people
    who find each other and get married
• One extreme success story is a woman who
  responded to a friend on FaceBook who needed a
  kidney donation
  – They had never met in person and now they are very
    close friends, the woman having saved the man’s life
       Danger of Social Networking
• People may not be what they seem
   – beware of cyberstalking
• Might keep people insulated/isolated
   – are you spending more time on-line with your FaceBook
     “friends” than you are socializing in person with real friends?
      • are we becoming a society of people who enjoy company only
      • could we be losing some of our socializing skills?
   – could promote laziness – instead of walking to your neighbor’s
     to talk, you just get on-line
• Could be a potential time waster
• Extended computer usage can be detrimental to your
   – this last one is not limited to social networking, but a lot of
     people play on their networks for hours at a time
      • we’ll talk about extended computer usage and your health later in the
• We live in a 24/7, need it now kind of society
• The social networks give us the ability to express
  ourselves NOW or find out the latest
   – through a tweet, a person tells their fans or friends what
     just happened (“you won’t believe who I just saw at the
• This capability has good and bad sides
   – the good is that you can express yourself immediately
     while the thoughts are coming to you
   – if something important has happened, you can get the
     word out quickly
   – on the other hand, maybe you should take some time,
     compose yourself, think about what you want to say,
     don’t express things while you are angry, etc
   – reputations can be damaged (yours and others) if you are
     too rash about something
     My Soapbox and Welcome To It
• Social networks give people the ability to express
   – But unlike the ability to express yourself to a few friends at
     work or school or home, through a social networking site, you
     could reach thousands or millions
   – And you could reach people anywhere in the world
• Is it your right to be able to express yourself?
   – In the US, we have that right although until we had the Internet,
     we didn’t have a mechanism for the common man to do this
• Should you express yourself
   – This is a different question altogether
      • why should people care what you think?
      • what if you have “dangerous” ideas?
      • what if your ideas are stupid or pointless?
• Just because you have the right and the ability, does that
  mean you should use it?

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