📡Communication Models

In the previous lesson, we examined rural development agencies and programmes — the schemes that channel resources to farmers and rural communities. But how do extension workers effectively communicate these programmes and new technologies to farmers? This lesson explores the theoretical models of communication that underpin all extension work.

Effective communication is the foundation of agricultural extension. Without it, even the best technology remains confined to research stations. Understanding these models helps extension workers diagnose why messages fail and how to improve information flow.

This lesson covers:

1. Five communication models — Aristotle, Shannon-Weaver, Berlo, Leagans, and Rogers-Shoemaker
2. Definitions of communication — by key scholars
3. Distortion types — Systematic, Fog, and Mirage
4. Key communication terms — Fidelity, Empathy, Propaganda, and more

All sections are frequently tested in IBPS AFO and NABARD exams.

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Communication Models

Each model below represents a different era’s understanding of how information flows from source to receiver. Earlier models are simpler and one-directional; later models incorporate feedback, encoding/decoding, and audience effects — reflecting the evolution from top-down lecturing to participatory extension.

1. Aristotle’s Model (384-322 BC)

The oldest and simplest communication model:

Speaker → Speech → Audience

• It was the first basic persuasive communication model
• Focuses on the speaker’s ability to persuade the audience
• One-way model with no feedback mechanism
• Best suited for: public speaking and persuasion

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2. Shannon-Weaver Model (1949)

Source → Transmitter → Signal → Receiver → Destination

With a Noise Source affecting the signal.

• Introduced the concept of noise (interference) in communication
• Best suitable for: Broadcasting of farm information
• Originally developed for telephone communication, later adapted for mass communication
• Key contribution: recognized that external disturbances can corrupt the message

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3. Berlo’s SEMCDR Model (1960)

Source → Encoding → Message → Channel → Decoding → Receiver

• Purpose of communication should be behaviour control
• Emphasizes the encoding and decoding processes
• Both source and receiver need shared communication skills, attitudes, knowledge, social system, and culture for effective communication
• Considers communication a two-way process with encoding at sender’s end and decoding at receiver’s end

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4. Leagans Model — CMCTAR (1963)

Communicator → Message → Channel → Treatment → Audience → Response

• The Communicator is the characteristic element of this model
• Best application: Field extension work
• Unique feature: includes Treatment (how the message is packaged/presented) and Response (audience’s reaction)
• Most practical model for extension workers because it considers the entire cycle from communication to feedback

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5. Rogers and Shoemaker Model (1971)

Source → Message → Channel → Receiver → Effects

• Added the concept of Effects — what changes occur in the receiver after receiving the message (knowledge gain, attitude change, behaviour adoption)
• Defined communication as: “the process by which messages are transferred from a source to a receiver”
• This model is significant because it connects communication directly to the adoption-diffusion process — the Effects element measures whether the message actually changed the farmer’s behaviour

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Definitions of Communication

Exam questions often ask “Who defined communication as…?” — matching the definition to the scholar is the key skill here.

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Distortion of Information

In any communication chain — especially in extension where messages pass through multiple intermediaries (researcher → subject matter specialist → extension worker → contact farmer → other farmers) — the original message can get corrupted. Understanding these three types of distortion helps diagnose communication failures.

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Key Communication Terms

These terms appear frequently in MCQs as definition-matching questions. Each has a precise meaning in the context of extension communication.

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Important One-Liners

These are standalone exam facts that do not fit neatly into the models above but are frequently tested.

• Communication is derived from the Latin word “communis” meaning common — emphasizing that communication creates a shared understanding between people
• Extension teaching is: Horizontal — meaning it is participatory and peer-to-peer, not a top-down hierarchical instruction
• Over-adoption may be due to: Insufficient knowledge — when farmers adopt a practice beyond recommended levels (e.g., excessive fertilizer use) because they lack complete understanding of the recommendation
• The communication channel most suited to inform about the existence of an innovation is: Mass media — mass media creates initial awareness, but interpersonal channels are more effective for persuasion and adoption

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Summary Cheat Sheet