Now these information cascades are precisely what we mean when we say crowds
are not so wise. They're easily influenced and they tend
to follow crowds even when crowds aren't necessarily correct.
Now these types of cascades tend to happen when people exchange information
with one another about what they're thinking.
And that's one of the assumptions that we made in the wisdom of crowds, is that we
can't have people exchanging information and telling each other what they think.
So this can't happen for the wisdom of Krause to hold, everyone has to make
their own guess. So one common example of this would be if
you're working on a homework assignment, and you have three of your friends here,
and three of your friends are all saying that the answer to one question is b.
So they all say yes and they're working together.
They've come up with the fact that the answer is B.
Now you may come along and think that the answer is A, but you don't want to be the
odd man out. So you decide to put that in your paper,
and you say, well, it's 3 against 1 so I may as well just put B because everyone
else has. Now, it might turn out that A is actually
the correct answer. One person came up with the idea that it
was B, and everyone else followed him, not wanting to be the odd man out.
So, now again this is great, but how does this have to do with networking?
Well, this really brings us to the whole idea behind social networks in which we
have people interacting and influencing one another.
And one example of that is on YouTube. And these types of information cascades
can explain why movies such as Gangnam Style and Charlie Bit My Finger Again
have gone viral. And we've seen them explode to even
billions of views. Gangnam Style has broken 1 billion.
The idea is that as you see more people watching these videos, you will also be
recommended to and you will want to watch them to see what's so great about them.
So we have information cascade here. Now it's also prevalent in platforms like
Facebook or Twitter, in which, you actually have big, large social networks
of people. And in Facebook, they're defined by
friend relationships where you might have, be friends with certain amount of
people and everyone else's friends with other people and so on and so forth.
And then the question is that people would be able to determine who the
intellectual people are in the crowd. So for instances if someone was standing
right here, they happen to be friends with a whole lot of people, happens to be
very influential. Than whatever this person does could have
an impact on what everyone else see's on their news feed's or whatever everyone
else does as well. And we have influence that way.