Spatial Diffusion

Model Assumptions

-Isotropic plain -Contacts identical -Distance decay

Edge

A connection or tie between two nodes

Node

An individual unit in the graph or system. (If it is a network of subway system, then each node represents a subway station)

Cultural Convergence

Sharing of technologies, organizational structures, and cultural traits • Role of communication & transportation • Proof of globalization?

Expansion Diffusion

Spread from one place to others after direct or indirect contact

Spatial Diffusion

The spread or movement of a phenomenon (idea or innovation) across space and time

Types of Expansion Diffusion

i. Contagious - rapid, widespread contact diffusion ii. Hierarchical: diffusion to large/important areas first, then lesser areas later

Steps of the Model

i. Lay grid over plain ii. Original innovator (I) starts in center cell iii. Overlay a Mean Information Field (MIF) iv. Select a cell by choosing a random 3-digit number v. Person in that cell adopts innovation vi. Repeat process for original cell I and for each cell A from previous generations

Hägerstrand's Computational Model

• A model of contagious expansion diffusion • Uses Monte Carlo modeling (meaning a random process)

Culture Hearths

• A nuclear area within which an advanced and distinctive set of culture traits, ideas and technologies develops • Source of diffusion

What kinds of things can "spread?"

◦ Disease ◦ Ideas ◦ Tools ◦ Technology ◦ Beliefs

Network

Graph or system; a set of units that may be (but are not necessarily) connected to each other

Innovation and Adoption

Innovation implies changes to a culture that result from ideas created within the social group itself and adopted by the culture

Relocation Diffusion

Innovation is carried to new areas by migrating individuals or populations

Contacts identical

People contacted or not (full transmission); identical

Distance decay

Probability of contact decreases with distance

Types of Spatial Diffusion

Relocation and Expansion

Isotropic plain

o Uniform flat area without borders o Evenly distributed and culturally-uniform population