INFO2040X mod4 kleinberg information networks and the world wide web v1

Articles, Blog

INFO2040X mod4 kleinberg information networks and the world wide web v1

INFO2040X mod4 kleinberg information networks and the world wide web v1


We’ve been using networks to
model a variety of things. We’ve used social networks to
represent the friendships among people, economic networks to capture the
links between buyers and sellers. And now we’d like to talk about
a different type of network, an information network which expresses
logical relationships among pieces of information. The heart of this
discussion will be sort of a key example of an information
network in modern society, which is the worldwide web,
something we use every day. The web is an application
built on the internet. And it was essentially
designed to solve a problem to fill in something the
internet lacked for the first two decades of its existence. All through the 1970s
and 1980s, the internet was good for allowing secure
access to remote computers. But there wasn’t really an easy way to
make files public to the whole world. That changed rapidly in the
year right around 1989, 1991, when Tim Berners-Lee and a small team
at CERN in Switzerland created the web. The web based on three
key ideas, really. One, it provided an easy
way to make documents, the web pages, public for
the whole world to see. The second was that it
gave users an easy way to view these pages using browsers. And the third, which is really
the heart of our discussion here, is that it was based on a way of
connecting these pages using links. And it was really this that
turned the web into a network. If you think about your own
experience using the web, this is sort of what you see, right? Say you’re reading a blog,
you see a post on the blog, you follow a link from that
post to a news article, you read that for a while, you
back up, you read another post, you follow a link there. Although we don’t always think about
it this way, what you’re really doing is walking around on a big
network where the nodes are pages and the edges are links. And you’re following links,
visiting other things, going in different directions. Let’s see how this works with a picture. Instead of thinking about
these actual web pages as they look on your browser
screen, let’s sort of take a bird’s eye view
of them, or at least kind of a conceptual view of them. And say suppose we’re starting at the
home page for a course about networks. And on this page, it
has the various things and it says we have a class blog
where students write blog posts. And it links to that blog. And so we click on that link
and we end up on the class blog and there’s a series of posts. One of them is about Cornell,
where the course is being taught. One’s about some company, we’ll
call it Company X. And maybe we’re interested in these, so we
follow links out of them. So the blog post about Company X leads
to a news article about that company. The post about Cornell actually
takes us to the Cornell homepage. And we explore around the
Cornell homepage for a while and we see they have a list of classes. We go there. And as we read down it, we see the
way down in that list of classes is a link to a course about networks. And we follow that link and we
actually end up back where we started. So we walked around, maybe
this took us five, 10 minutes, we were aimlessly exploring. But in the graph on this network,
what we saw was a set of nodes that we were traversing, and
we were following these links and we actually followed a path that
brought us back to where we started. Now because we’re so familiar
with this, from our experience, we might think that, well, how else
could you have organized the web? This just seems like
an obvious decision. But in fact there are lots of
ways that we organize documents. We put them in folders, we put them
in taxonomies or other organizations. We could even sort them alphabetically. In fact, structuring
the web as a network was both inspired and non-obvious. It’s really what gave it the kind
of experience that we now see today. And it really gives it
its organizing principle. But the idea to organize the web as
a network didn’t come out of nowhere. It was really based on an idea
called hypertext that had really been pursued very passionately
by a group of computer scientists beginning with researchers
like Ted Nelson in the 1960s. The idea was to take text, the way
we organize in books or articles, and just sort of explode
the linearity of that text. Normally text just is
one thing after another. But hypertext was designed to break it
apart and put into a conceptual space where the links between the pieces of
information could be made explicit. Tim Berners-Lee and
his team at CERN when they created the web,
Tim Berners-Lee had been someone who read about hypertext. He knew about hypertext and it was in
his mind when he was building the web. And so the architecture,
the web was very much based on this idea of exploding text and
exposing the logical links explicitly. And through the web,
the idea of hypertext was brought to a global
audience on a scale that really no one could
ever have imagined. But of course, the idea of networks
on information and information having network structure, that didn’t
start with the web or with hypertext. It really draws on a bunch
of intellectual precursors that reach back to much
earlier pre-technological eras. And so these intellectual foundations
for network structure and information is something that drives how we think
about the web and how it’s organized. And that’s what we’ll talk about next.

Leave a Reply

Your email address will not be published. Required fields are marked *