Introduction to Theories of Communication Effects: Diffusion Theory

Introduction toTheories of Communication Effects:

Diffusion Theory

A service of the

Communication Science & ResearchResource Group

Recap: Theory mapMODEL STAGE (Early --> Late)

Messagelearning

Reasonedaction

Sociallearning

Diffusion

Attention…….Comprehension…….Yielding…..Retention……………….. Action

Attitudes Subjective norms.….Intention to act……………………………. Action Perceived control

Attention...Retention...Reproduction...Motivation…………………..Performance

Knowledge……Persuasion...Decision…….Implementation….Confirmation

Origins of Diffusion Theory (Everett Rogers)

George Washington Carver (1896)Iowa State agricultural extension system and “movable schools”

Gabriel Tarde (1903) The Laws of Imitation - the S-curve

Ryan & Gross (1943)Diffusion of hybrid corn varieties 1930-1940

Post-WWII modernizationGreen Revolution, family planning

News diffusion studies (1960s)Kennedy assassination

What is diffusion?

“The process by which an innovation is communicated through certain channels over time among members of a social system.”

Rogers, 1995

What is diffusion?

“The process by which an innovation is communicated through certain channels over time among members of a social system.”

Rogers, 1995

What is diffusion?

“The process by which an innovation is communicated through certain channels over time among members of a social system.”

Rogers, 1995

What is diffusion?

“The process by which an innovation is communicated through certain channels over time among members of a social system.”

Rogers, 1995

What is diffusion?

“The process by which an innovation is communicated through certain channels over time among members of a social system.”

Rogers, 1995

What is diffusion?

“The process by which an innovation is communicated through certain channels over time among members of a social system.”

Rogers, 1995

Innovation = any idea, attitude, or behavior that is new to the members of a social system

Critiques of diffusion

• Pro-modernity, anti-tradition bias• Pro-technology bias• Ignores structural inequity• Widens the have-have not gap• Manipulative and top-down

--> Like any theory, diffusion can be and has been misused

Key concepts

• Innovation-decision process• Attributes of innovations• Adopter/audience categories• Homophily-heterophily• Opinion leaders• Strength of weak ties

Innovation-decision process

Diffusion curve (S-curve)

Time

0

100

Cumulativepercent

who haveadopted

Rate of diffusion

Time

0

100

Take off

Cumulativepercent

who haveadopted

Time

0

100

Fasterdiffusion

Cumulativepercent

who haveadopted

Rate of diffusion

Time

0

100

Fasterdiffusion

Slowerdiffusion

Cumulativepercent

who haveadopted

Rate of diffusion

The KAP Gap

The KAP Gap

What predicts rate of diffusion/ adoption?

1. Attributes of the innovation

2. Attributes of the audience

3. Environmental constraints/facilitators

4. Characteristics of the communication system

1. Attributes of the innovation

Relative advantage> Does the new behavior offer any

advantage over the current behavior?

Compatibility> Is the new behavior compatible with

current behaviors, beliefs, and values?

Complexity> How difficult is the new behavior to

perform?

Trialability> Can it be tried without too much risk

before making a decision?

Observability> Are there opportunities to see what

happens to others who adopt this behavior?

1. Attributes of the innovation

2. Attributes of the audience

2. Attributes of the audience

• Education• Literacy• Social mobility• Size & connectedness of networks• Degree of social participation• Attitude toward change• Tolerance for ambiguity & risk• Exposure to media• Exposure to interpersonal channels• Information seeking behavior

2. Attributes of the audience

3. Constraints & facilitators

• Access to education• Access to information & means of

communication• Access to the innovation • Normative pressure• Disposable income, ability to absorb loss

4. Communication system

Key concepts:Homophily-heterophily

4. Communication system

Key concept:Strength ofweak ties

Diffusion Theory

Key concept:Opinion leader

Communication Network Among Women in a BangladeshVillage with Jiggasha Group Membership Indicated

Trishal Village No. 7, 1992JHU/CCP & MITRA & Associates

Jiggasha Member (28%)

Knowledge

Putting it to work

Confirmation

Persuasion

Decision

Implementation

Where is your audience?What can you tell them and how?

Diffusion Theory addresses all stages in the hierarchy of

effects, but is particularly useful for thinking about

Knowledge and Persuasion.

Using Diffusion Theory in ProgramsIdentify how audience thinks of the innovation• Relative advantage, complexity, etc?

Identify people who are key network members• Who is nodal?• Who is an opinion leader?

Identify messages that address concerns about the innovation

• Show the benefits• Show how to do it in simple terms• Show what happens if you do it• Show how new behavior fits with or grows out of

current practices• Motivate or provide opportunities to try• Encourage discussion

Next Week:

Bounded normative influence

How an innovation becomes a norm

Looking ahead