Information Flow,

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Lecture 20
Information Flow, Diffusion and Homophily
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Information Flow

• One way to understand IC is to examine the
  interpersonal networks through which messages
  flow.
• These human information pathways represent ways
  in which
• information flows,
• relationships form, and
• influence occurs in interpersonal relationships.

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What is Diffusion?

• Diffusion is the process by which
• (1) information (about an innovation),
• (2) is communicated through certain channels,
• (3) over time,
• (4) among members of a social system,
• (5) with certain effects.
• The emphasis of communication is on sharing
  information, whereas diffusion is a particular
  form of communication concerned with the flow of
  new ideas through society.

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Models of Diffusion

• 1. Hypodermic Needle model
• 2. Two-Step Flow model
• 3. Multi-Step Flow model

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Hypodermic Needle Model

• It postulated that the
• mass media has a direct,
• immediate, and powerful
• effect on a passive mass audience.
• So, the audience is viewed as being connected to
  the media but not to each other.

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Two-Step Flow Model

• This model resulted serendipitously from a study
  of the 1940 presidential election. It was
  designed with the Hypodermic needle model in mind
  but it was found almost no voting choices were
  directly influenced by the media.
• Instead, the research indicated that information
  flowed from the media to opinion leaders and from
  them to less involved members of society
  (followers).

Opinion leaders
Society
Mass media
followers
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Multi-Step Flow Model

• Information that flows in a culture or group can
  be filtered or passed through a series of opinion
  leaders before reaching all segments of the group
  or culture.
• The exact number of steps depends upon
• the intent of the source,
• the availability of the information (mass media),
• the extent of exposure, and
• the nature and salience of the information to the
  receiver.

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Homophily vs. Heterophily

• Homophily is the degree to which pairs of
  individuals who interact are similar.
• Heterophily is the degree to which individuals
  are different.

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Homophily Principle
Income, Education, Age, etc.

• Homophily High
• Homophily Middle
• Homophily Low

Heterophily
Heterophily
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Dimensions of Homophily

• Physical homophily
• Background homophily
• Attitude homophily
• Value homophily
• Personality homophily

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Homophily in Individuals

• More efficient and effective communication occurs
  between homophilous individuals.
• Communication between heterophilous individuals
• requires more effort,
• is less rewarding, and
• is more likely to produce dissonance.

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Homophily as a Barrier to Diffusion

• While homophilous communication may be easy and
  enjoyable it is a barrier to innovations because
  new ideas diffuse quickly within networks, but
  not between them.
• One implication is that when encountering a
  social system characterized by homophilous
  communication patterns, change agencies should
  work with different opinion leaders throughout
  the system.

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Change Agents

• An individual who influences peoples (innovation
  adoption) decisions in the direction desired by a
  change agency.
• A change agency is an organization which views
  part of its function as producing changes in
  society.
• Change agents attempt to link two social systems
  the change agency (source) and the audience
  (receivers).

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Factors Affecting Agents Success

• It is positively related to
• the extent of effort in contacting clients.
• the degree to which the diffusion program is
  compatible with client needs.
• the extent of homophily with clients,
  particularly on the education (background)
  dimension.

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Homophily Principle and IC

• Homophily information sharing
• Homophily and persuasion
• Optimal heterophily

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Measuring Homophily

• Attitude Dimension
• Background Dimension
• Value Dimension
• Appearance Dimension
• Developed by McCroskey, Richmond, and Daly (1975)