Diffusion of innovations and extension teaching methods
How new farm practices spread: stages of adoption, Rogers' adopter categories, what makes an innovation catch on, and the extension methods for each stage.
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A new variety, a better way to store grain or a cheaper irrigation method helps no one until farmers use it. How new ideas spread through a community, and how extension services can help them spread faster and to the right people, is the subject of diffusion of innovations research, and the reason extension education exists.
The framework set out by the sociologist Everett Rogers in Diffusion of Innovations (first edition 1962) is still the core of extension syllabi everywhere: the stages farmers go through, the categories of adopters, the attributes that make an innovation spread, and the teaching methods suited to each stage.
Where the theory came from
Much of the theory grew out of rural sociology. In a classic study published in 1943, Bryce Ryan and Neal Gross interviewed farmers in two Iowa communities about when they had started growing hybrid maize. Although hybrid seed clearly paid, it took about fourteen years for nearly everyone to adopt it. Most farmers first heard of it from salesmen, but were persuaded by their neighbours. Plotting the year of adoption gave a bell-shaped curve, and the cumulative number of adopters an S-shaped one. Thousands of studies since, across crops, countries, health and technology, have found similar patterns.
The innovation–decision process
An individual's adoption is a process, not a moment. Rogers describes five stages:
- Knowledge: the person learns the innovation exists and something of how it works.
- Persuasion: forms a favourable or unfavourable attitude towards it.
- Decision: chooses to adopt or reject it, often after a small trial.
- Implementation: puts it into use, adapting it ("re-invention") along the way.
- Confirmation: seeks reinforcement and may reverse the decision (discontinuance) if results disappoint.
An older and still widely examined version, from George Beal and Joe Bohlen (1957), names five adoption stages: awareness, interest, evaluation, trial and adoption.
Adopter categories
People adopt at different times. Rogers divided a population by how many standard deviations each person's adoption time lies from the mean.
| Category | Share | Typical characteristics |
|---|---|---|
| Innovators | 2.5% | venturesome; resources to absorb risk; contacts outside the community; sometimes seen as outsiders locally |
| Early adopters | 13.5% | respected locally; the highest share of opinion leaders; others watch what they do |
| Early majority | 34% | deliberate; adopt just before the average; many contacts with peers |
| Late majority | 34% | sceptical; adopt from economic necessity or peer pressure; fewer resources |
| Laggards | 16% | traditional; often the most resource-poor and risk-averse; may adopt when the innovation is already being replaced |
Planning by adopter category
An extension worker serves a village of 400 farming households and is introducing an improved storage bag.
Applying Rogers' percentages: innovators 400 × 0.025 = 10; early adopters 400 × 0.135 = 54; early majority 400 × 0.34 = 136; late majority 136; laggards 400 × 0.16 = 64 households.
The practical lesson is not the exact numbers, which vary from place to place, but the strategy: identify and work closely with the early adopters, because they include the opinion leaders whom the early majority watch. Once roughly 10 to 20 per cent of households have adopted, the S-curve often steepens as adoption becomes self-sustaining through neighbours. The late majority and laggards usually need the innovation made cheaper, simpler or less risky, or credit and input supply arranged, rather than more persuasion.
A caution about categories
The label "laggard" can blame people for what is often a rational response to their situation: little land, no credit, high risk, or an innovation designed for someone else. Rogers himself warned against a pro-innovation bias (assuming every innovation should be adopted by everyone) and an individual-blame bias. Good extension asks whether the innovation fits the farm, not only whether the farmer is ready.
What makes an innovation spread
Rogers identified five perceived attributes that explain much of the difference in how fast innovations are adopted:
- Relative advantage: how much better it is than what it replaces: more profit, less labour, less risk, prestige.
- Compatibility: how well it fits existing values, practices, needs and farming systems.
- Complexity: how hard it is to understand and use. Simpler spreads faster.
- Trialability: whether it can be tried on a small scale first. A new seed on one plot is trialable; a tractor is not.
- Observability: how visible the results are to others. A greener, taller crop by the roadside advertises itself; a soil conservation practice whose benefit appears over years does not.
Innovations with high relative advantage, compatibility, trialability and observability, and low complexity, spread fastest. Extension can improve several of these: by demonstrating results (observability), by supplying small packs for trial (trialability), and by adapting the practice to local conditions (compatibility).
Extension teaching methods
Extension methods are traditionally grouped by how many people they reach at once.
| Group | Methods | Strengths | Limits |
|---|---|---|---|
| Individual | farm and home visits, office or phone calls, personal messages, one-to-one digital advice | tailored, builds trust, best for the trial and adoption stages | slow and costly per farmer |
| Group | method demonstrations, result demonstrations, field days, meetings, farmer field schools, study tours, exhibitions | learning from peers, discussion, seeing results | needs organisation; reaches those who attend |
| Mass | radio, television, print, posters, mobile messages, social media, videos | reaches many cheaply and quickly; best for awareness | one-way; little adaptation to individual farms |
Two group methods are examined especially often:
- A method demonstration shows how to do something, step by step, so that people can do it themselves: grafting a mango seedling, calibrating a sprayer, treating seed.
- A result demonstration shows what a practice achieves, by comparing it with the usual practice under local conditions, usually as side-by-side plots on a farmer's own field. It is associated with Seaman Knapp's farm demonstration work in the southern United States in the early 1900s and is still a pillar of extension worldwide.
Matching method to stage: mass media work best for awareness; group methods and demonstrations for interest and evaluation; individual contact and small trials for trial and adoption. Most successful programmes combine all three, now increasingly through digital channels such as farmer video, interactive voice response and messaging apps, which can lower the cost of individual contact.
Educational research summarised in Edgar Dale's cone of experience (1946) is often cited in extension: people retain more from direct, purposeful experience and demonstrations than from words alone. Farmer field schools, where groups learn by observing and experimenting in a field through a whole season, build on this idea.
Key points
- Diffusion research (Ryan and Gross on hybrid maize, 1943; Rogers, 1962) shows a bell-shaped curve of adoption times and an S-shaped cumulative curve.
- Innovation–decision process: knowledge, persuasion, decision, implementation, confirmation (older: awareness, interest, evaluation, trial, adoption).
- Adopter categories: innovators 2.5%, early adopters 13.5%, early majority 34%, late majority 34%, laggards 16%.
- Opinion leaders are concentrated among early adopters; working with them speeds diffusion.
- Attributes: relative advantage, compatibility, complexity (negative), trialability, observability.
- Mass media suit awareness; group methods and demonstrations suit interest and evaluation; individual contact suits trial and adoption. Method demonstrations teach skills; result demonstrations prove outcomes.
What the exams ask
- School-leaving and entrance papers: the stages of adoption, the adopter categories and their percentages, and examples of individual, group and mass methods.
- Degree and research-fellowship entrances in extension: Rogers' model in detail, attributes of innovations, opinion leadership, critiques of diffusion theory, method versus result demonstration, and choice of method by stage.
- Professional and civil-service examinations: designing an extension campaign for a new technology, farmer field schools, digital extension and reaching resource-poor farmers.
Described in general terms: the kind of examination, not a past paper. Laisha never reproduces exam questions.
Questions people ask
Why do some good innovations spread so slowly?
Usually because one of the attributes is weak: the benefit is small or invisible, it does not fit the farming system, it is complex or risky, or it needs credit, inputs or markets that are not available. Extension alone cannot fix missing infrastructure.
Who are opinion leaders, and how are they found?
They are people others turn to informally for advice. They tend to be well connected, respected and slightly more innovative than their neighbours. Extension workers find them by asking farmers whom they consult, and by watching whose practices others copy.
Is adopting always the right outcome?
No. An innovation that suits large irrigated farms may be wrong for a small rainfed one. Good extension helps farmers decide, and rejection of an unsuitable practice is a sound result.
Sources
- Rogers, E. M. Diffusion of Innovations, 5th edition. Free Press, 2003.
- Ryan, B. and Gross, N. C. "The diffusion of hybrid seed corn in two Iowa communities." Rural Sociology 8, 15–24 (1943).
- Beal, G. M. and Bohlen, J. M. The Diffusion Process. Iowa State College Agricultural Extension Service, Special Report 18, 1957.
- van den Ban, A. W. and Hawkins, H. S. Agricultural Extension, 2nd edition. Blackwell Science, 1996.
- Swanson, B. E., Bentz, R. P. and Sofranko, A. J. (eds) Improving Agricultural Extension: A Reference Manual. FAO, 1997.
Discussion
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