Human–Computer Interaction (HCI)

Meaning

• Human–Computer Interaction (HCI) is the study and practice of how people interact with computers, machines, and digital systems.
• It focuses on designing user-friendly interfaces that make it easier for humans to use technology effectively.
• HCI is interdisciplinary, combining computer science, psychology, cognitive science, ergonomics, and design.

Example: A farmer using a touchscreen kiosk for accessing market prices is part of HCI.

Theories of Multimedia Learning

Multimedia learning means using words, pictures, sounds, and animations together to improve learning. The main theories are:

1. Dual Coding Theory (Paivio, 1971, 1986)

• The human brain processes verbal information (text, speech) and non-verbal information (images, visuals) separately.
• Learning improves when both are combined.
   Example: An extension worker showing farmers a video (visuals + narration) about pest control.

2. Cognitive Theory of Multimedia Learning (Mayer, 2001)

Proposed by Richard E. Mayer, it is the most widely used theory.
It is based on three assumptions:

1. Dual-channel assumption – Humans have separate channels for processing words and pictures.
2. Limited capacity assumption – Each channel has a limited capacity.
3. Active processing assumption – Learners must actively process information to build meaningful knowledge.

👉 Example: E-learning modules for agriculture must avoid information overload; instead, they should use short videos, images, and simple text.

3. Constructivist Learning Theory (Bruner, Piaget, Vygotsky)

• Learners construct knowledge based on their experiences.
• Multimedia tools (like simulations, interactive videos, VR) help learners experiment and discover.
  👉 Example: A virtual reality app where farmers can simulate the effects of fertilizer application.

4. Multimedia Principle (Mayer, 2005)

• People learn better from words + pictures than from words alone.
  👉 Example: An agricultural extension leaflet with diagrams + explanations is more effective than plain text.

Research shows that multimedia-based agricultural training increases farmers’ knowledge retention by up to 35–40% compared to traditional lectures (FAO & World Bank reports, 2015).

Sweller’s Cognitive Load Theory (CLT)

• Meaning: Proposed by John Sweller (1988, University of New South Wales, Australia), this theory explains how human working memory is limited and how instructional design should avoid overloading learners with unnecessary information.
• Types of Cognitive Load:
  1. Intrinsic Load – Complexity of the material itself (e.g., learning soil types in agriculture).
  2. Extraneous Load – Unnecessary effort caused by poor instructional design (e.g., confusing diagrams, irrelevant animations).
  3. Germane Load – Productive effort devoted to actual learning (e.g., solving farm management problems with worked examples).
  4. Sweller’s experiments in the 1980s on problem-solving in mathematics led to this theory. It has since been widely applied in e-learning, multimedia learning, and

Mayer’s Cognitive Theory of Multimedia Learning (CTML)

• Meaning:
  Developed by Richard E. Mayer (2001, University of California, Santa Barbara), this theory explains how people learn better from words and pictures together rather than from words alone.
• Key Idea:
  Learners process information through two channels (dual coding):
  • Visual (pictures, diagrams, videos)
  • Auditory (spoken words, narration)

Both channels have limited capacity, so instructional design must be optimized.

• Principles of CTML (Selected):

1. Multimedia Principle – Use pictures + words, not just words.
2. Modality Principle – Spoken words + images are better than written words + images.
3. Redundancy Principle – Avoid presenting the same information in multiple formats unnecessarily.
4. Coherence Principle – Exclude irrelevant sounds, images, or text.
5. Segmenting Principle – Present information in smaller, manageable chunks.

• Mayer’s theory is based on Cognitive Science + Paivio’s Dual Coding Theory (1971). He tested his principles through controlled experiments with multimedia lessons (e.g., animations of scientific processes).
• Extension Education Use:

• • Creating farmer-friendly videos, apps, and e-learning modules that use clear visuals, short audio explanations, and step-by-step demonstrations.
  • For example: A video on Integrated Pest Management (IPM) that shows images of pest symptoms along with narration, instead of only text.

In short:

• Sweller (1988) – CLT → Focus on avoiding overload in learning.
• Mayer (2001) – CTML → Focus on how multimedia (words + visuals) improves learning.