Social Media Mining: An Introduction

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CUUS2079-07 CUUS2079-Zafarani 978 1 107 01885 3 January 13, 2014 17:17

7.1 Herd Behavior 181

Information

Diffusion

Explicit

Network

Global

Information

Network

Observability

Information

Availability

Herd

Behavior

Information

Cascades Diffusion ofInnovationsEpidemics

Local

Information

Implicit

Network

Figure 7.1. Information Diffusion Types.

whether to become infected or not and infection is considered a random nat-

ural process, as long as the individual is exposed to the pathogen. Figure7.1

summarizes our discussion by providing a decision tree of the information

diffusion types.

7.1 Herd Behavior

Consider people participating in an online auction. Individuals are con-

nected via the auction’s site where they cannot only observe the bidding

behaviors of others but can also often view profiles of others to get a feel

for their reputation and expertise. Individuals often participate actively in

online auctions, even bidding on items that might otherwise be considered

unpopular. This is because they trust others and assume that the high num-

ber of bids that the item has received is a strong signal of its value. In this

case,herd behaviorhas taken place.

Herd behavior, a term first coined by British surgeon WilfredTrotter

[1916], describes when a group of individuals performs actions that are

aligned without previous planning. It has been observed in flocks, herds

of animals, and in humans during sporting events, demonstrations, and

religious gatherings, to name a few examples. In general, any herd behavior

requires two components:

1. connections between individuals


2. a method to transfer behavior among individuals or to observe their
   behavior