[ 4.1 Getting Started ]

- In 90s, web was a collection of web pages.  Now it's a highly
interactive virtual world characterized by its dependence on
people interacting with each other.

- Web 2.0 - term for the new people-centric web - sort of the second
generation of online communities.  Includes social networking, blogs,
syndication, wikis, and folksonomies.
- Key ingredient is that it's built by the people.

[ 4.2 Blogs ]

- Blog = weblog
- online equivalent of a diary or personal journal.
- implemented as a webpage that is used to post text images, sound
files, videos, and links (pretty much anything)
- Usually they are created and updated using blogging software
(blogger, livejournal, etc) instead of by writing HTML in a file.
- Blogs often contain a blogroll - a list of other blogs that the
blogger likes/reads.
- Blogs really hit the mainstream in 2004
- The collection of all blogs online and the connections between them
(formed by blogrolls) is called the blogosphere.
- Estimated that the size of the blogosphere doubles every 6 months
- Blogs have significantly impacted culture, especially because
now they are often seen as a form of outreach and journalism.
- For example, during political debates on TV, often there will be
journalists or pundits blogging in real-time with their opinions.
- Often bloggers can report on information faster than in traditional
journalism, because there's no cycle of editing and publishing.
- Can report on topics ignored by the mainstream media.
- Also in 2002, many blogs focused on comments by U.S. Senate Majority 
Leader Trent Lott. Senator Lott, at a party honoring U.S. Senator Strom 
Thurmond, praised Senator Thurmond by suggesting that the United States 
would have been better off had Thurmond been elected president. Lott's 
critics saw these comments as a tacit approval of racial segregation, 
a policy advocated by Thurmond's 1948 presidential campaign. This view was 
reinforced by documents and recorded interviews dug up by bloggers. 
Though Lott's comments were made at a public event attended by the media, 
no major media organizations reported on his controversial comments until 
after blogs broke the story. Blogging helped to create a political crisis 
that forced Lott to step down as majority leader.
- Consequences 
  - You may not be as anonymous as you think in a blog - watch out
if you criticize people.  Various lawsuits have been brought before the 
courts to unmask anonymous bloggers or to sue for damanges after a
defamed reader uncovered the identity of a blogger.
  - People have been fired from their jobs for commenting about their
work in their blogs in a way the employers didn't like.

[ 4.3 Social Networking ]

- Like real social networks, virtual social networks are formed around
common interests, experiences, or friends.
- Social networking services allow maintaining these social networks 
online.
- Most social networking systems involve creating a profile, where you 
list various attributes about yourself.  Varies depending on what the
service is designed for, but might include things like birth date, 
schools attended, your interests, and favorite movies or singers.
- The main type of social networking website consists of a large directory 
of people, a way to share information (including your profile), and a
way to make connections with other people.  This connection is sometimes
called "friending"  (Myspace, facebook, friendster, etc)
- So not only can you meet people you already know in the real world,
you can often search for other people who have similar interests as yourself,
to meet people you wouldn't otherwise meet.
- No way to stop people from posting false information - this can especially
cause a lot of heartaches on dating websites, which can also be seen
as social networks.  Remember that everyone on the internet, until you
meet them in person, is really a stranger.  As House says, People lie.
- Never post critical identifying information like SSN

[ RSS ]

- An RSS feed or channel is a data format that allows for displaying a 
time-stamped list of newly-posted or updated content on a website, such
as a blog or news articles.
- RSS feeds can be polled periodically for updates by an RSS client.
- RSS = really simple syndication
- Podcasting = when the RSS feed contains links to audio files instead of
links to blog entries or new articles.

- RSS clients are called RSS aggregators or RSS readers.
- They let you "subscribe" to any number of feeds and alert you in various
methods when a the feeds change.
- Online aggregator services like bloglines, or google reader, (and
customizable portal sites like igoogle and my yahoo), or standalone 
applications, or aggregators are now built-in to popular email apps like
web browsers (IE7, Firefox [live bookmarks]), 
and email-clients (Thunderbird, Outlook)
- Can view an individual feed in the main area of a web browser.
- Facebook example

Often websites that offer syndication will advertise the feeds with
a little orange feed icon.  Look for RSS or Atom.

[ Wikis and folksonomies ]

- Web2.0 sites often focus on collecting, organizing, and storing data.
(e.g. For social networking sites, the data is info about people)
- A wiki focuses on collecting information about a specific topic in
a rather freeform manner, and
- a folksonomy focuses on tagging existing data using an informal 
classification scheme (formal classifications are called taxonomies)

WIKIS

- A wiki is webserver software that provides the capability to create
and edit webpage content using a web browser, rather than writing HTML code.
- Wikis are usually used to make collaborative websites, where the editing
is done by the users of the website.
- On many wikis, the pages are not protected in any way, so anyone can
start a new page or edit the content on any page.  
- Wikis rely on the trustworthiness of the users to publish good content.
- Wikipedia: constantly being added and updated, resulting in an amazingly
current product.  However, the quality is uneven and inconsistent, 
there often is some cultural bias, and since anyone can edit it, you cannot
rely solely on Wikipedia for research.
- Possible to find wikis on lots of topics, some are public and open to
everyone, others are restricted to a smaller group of people who use it
to organize their own projects.

- Another type of application similar in spirit to Wikis are collabor-
ative office software.
- Allows for use of a word processor, spreadsheet, or presentation program
within your web browser.  
- Often one can give permission to others to view and edit your documents
(this is what makes it collaborative like a wiki).
- Google Docs & Spreadsheets (and now presentations)

FOLKSONOMY

- Information must not only be accessible, it must be searchable to get
the most out of it.
- Search engines use programs called spiders to crawl the web and look
for keywords on webpages, and use them to form an index.
- The problem is that spiders are computer programs, and computer programs
are only as smart as the person who creates them.  So it's impossible for
spiders to understand the purpose of the webpages they crawl, because 
they can't understand natural language.  
- The best way for a search engine to work would be to have people identify
the best keywords for every webpage out there (called tagging).  
- It's infeasible to do this for every webpage, but it's possible for
some webpages and for other types of media.  This leads to a folksonomy.
- del.icio.us - best example.  Allows people to upload their bookmarks,
tag them, and share them by allowing others to search by tags.
- Flickr for pictures.

[ 4.6 Discussion groups ]
Mailing lists
- forum where people use email messages to share information with each
	other.
- some are small, some are large (thousands of subscribers)
- some are open to all, some are restricted
- moderated list: list owner (moderator) posts all messages to the group,
	or individual messages have to be approved first
- unmoderated list (interactive mailing list): no approval required
- lurk: only 10% of subscribers post
- subscribing to a list:
	- signing up can be done by sending an email or on the web
	- regular subscription vs digest subscription
	- two important addresses: the command address, and the list
		distribution address -- don't confuse them!
	- run through example of commands (sub, unsub) [listserv, majordomo]
- mailing list netiquette - same as we talked about before
	- don't flame, be careful with humor, etc
- thread

Web-based discussion groups
- can be a message board (forum) or web-based mailing list
	- a message board is a site where people can read/post messages,
		reply to messages, and track discussion threads
	- web-based mailing list is a regular email list with a web-based
		interface
- message boards
	- some require registration to post and/or view messages
	- voting polls, opinion surveys, topical discussion boards, product
		review forums
	- examples are support forums for products, epinions.com, amazon.com's
		reviews
- web-based email list
	- taking a simple email list one step further by adding a web
		interface on top
	- but the messages to the list are still sent out in plain email, just
		like before
	- create your own at groups.yahoo.com and other sites
	- many web-based email lists now include other perks like access
		to old messages online, ability to post through the web, create
		polls, group calendar, store files/photos

USENET
- the oldest collection of message boards on the internet 
- predates the web (created in 1979)
- similar to BBS (bulletin board systems) in the 1980's except through
	the internet, not by dialing in
- not many people know about USENET, less than 5% use it
- since it predates the web, operates under NTTP (network news transport
	protocol)
- newsgroups, each post is called an article (but usually not news related)
- each article contains a header and a body like an email
- in fact, usually your email client doubles as a news reader
- to read and post on USENET, you need a news client and access to an NNTP
	server, however, you can get by without either one by using a web-based
	usenet gateway online
	- visit groups.google.com (not the same as regular google)
- newsgroups are organized hierarchically into categories
	- top level categories include: biz comp sci misc soc (social issues) 
		talk (debates) news rec (hobbies/recreation) alt (alternative hierarchy)
	- ex: comp.ai, rec.collecting.sport.baseball, misc.jobs.resumes
- creating a newsgroup is very difficult (lots of red tape) unlike
	creating a web-based discussion group (ala yahoo)
	alt.tv.dinosaurs.barney.die.die.die
- netiquette - same things as before, very public, stay on topic

[ 4.7 IRC, web-based chat, IM ]

REAL-TIME COMMUNICATION
- in contrast to what we've talked about so far
- IRC (internet relay chat)
	- very old, operates on a system of IRC servers, each
		of which has various chat rooms
	- need a special program (IRC client)
- web-based chat (chat rooms)
	- many chatrooms on various topics, some moderated, some not
	- sometimes special hosts in chat (celebrities)
- instant messaging
	- most popular use is for two people to chat directly to each
		other, but also supports chatrooms
	- was not part of original internet, that's why each network is 
	not compatible with others
	- need to download a client
	- AIM, MSN messenger, yahoo messenger, ICQ