General Principles of Diffusion

1
General Principles of Diffusion
2
Diffusion A Definition

• Diffusion is
• the process of spread in geographic space and
  growth through time of an innovation, idea or
  piece of information.

3
General Rule

• The rate of diffusion through an area of space is
  directly influenced by the distance from the
  source area and the available infrastructure.

4
Factors that Influence Diffusion

• Resistance
• Neighborhood Effect

5
Resistance

• Acceptance of an idea, innovation or new
  information is not automatic. If the innovation
  is resisted, this will decrease the rate of
  adoption and diffusion. Urban dwellers are less
  resistant to new information than rural dwellers.
  Resistance is highly influenced by both
• culture and economics.

6
Neighborhood Effect

• An innovation will be more likely to be adopted
  first close to its source area and then later at
  greater distances.

7
Types of Diffusion

• Wave
• Hierarchical
• Relocation
• Contagious

8
Wave Diffusion

• Wave diffusion is most closely associated with
  the neighborhood effect. In this form of
  diffusion an innovation, idea or piece of
  information emanates from a single source area
  and radiates outward with decreasing intensity as
  distance increases from the source area. The
  effect is similar to the ripple effect produced
  when you throw a stone into a pond.

9
Hierarchical Diffusion

• Occurs when an innovation or idea moves through
  the urban hierarchy both horizontally and
  vertically. The innovation originates in the
  largest city, passing through its surrounding
  towns first (horizontal movement) and then
  proceeds down the hierarchy vertically to the
  next largest city and its surrounding towns and
  so on until the innovation has saturated the
  hierarchy.

10
General Rule

• The rate of diffusion within the urban hierarchy
  is directly related to the density of the
  infrastructure connecting the cities and towns
  within the hierarchy.

11
Relocation Diffusion

• Occurs when an individual or group comes into a
  new area and brings with them new ideas and
  innovations which then may spread through a
  region as result of wave, hierarchical, or
  contagious diffusion. Through relocation
  diffusion, innovations appear to jump across
  large distances

12
Contagious Diffusion

• Occurs when an idea, innovation, piece of
  information, or disease, spreads as a result of
  one-to-one contact. Contagious diffusion may be
  aided by both relocation and hierarchical
  diffusion.