Diffusion research
In geographical diffusion research , the spread (compare diffusion , physics) of information, innovations and human activities (compare human geography ) in space is researched: What determines the path of spread of a disease, a technical innovation or a culture?
Spatial diffusion
The starting point for research into a process of expansion in space is the observation of an innovation - for example the introduction of a new product ( economic geography ), the application of new ideas; In general, the spread of activities or objects that are viewed as new by an individual or a social group - which spreads over time with the help of interpersonal contacts and ultimately mostly completely covers a spatial unit.
The innovation is passed on from a person who has already taken it over (adoptor) to one or more other people. The characterization of the spread of an innovation will be discussed below. First of all, the process of conscious adoption of an innovation can be characterized as follows:
- The willingness and speed of adoption of an innovation grows with the strength of the perception of its relative advantage
- The more an innovation corresponds to the existing values, norms and the experiences of everyday practice, the greater the early acceptance and thus the speed of adoption.
- The more complex it is and the more new knowledge and skills are required to use it, the slower it is to integrate an innovation into everyday life.
- If an innovation offers opportunities for testing and adaptation and z. B. can be tested on a small basis, the sooner uncertainties can be eliminated and decision-making processes accelerated.
- The easier it is for the potential adoptor to observe and evaluate an innovation process or the experiences made with a product, the faster the decision to take over will be made.
Forms of spatial diffusion
The Swedish researcher Torsten Hägerstrand developed the first approaches to a closed geographic innovation diffusion theory in his publication The Propagation Of Innovation Waves (1952). At the center of his research were the laws governing the spatial distribution of innovations. His methodological goal was to represent and simulate the diffusion process as realistically as possible with the help of mathematical models in the form of computer algorithms. Based on the assumption that the dissemination of an innovation (in the contact type) is always linked to personal contacts between people, one of his basic assumptions was the existence of a communication network, which he called the "mean information field". Within this field, as the distance from the information center increases, it becomes more and more unlikely to be supplied with information. The probabilities can be determined statistically and thus easily converted into a mathematical model.
Expansive diffusion
In the case of expansive diffusion, the information carriers (adopters) largely remain at the place of origin. Between two points in time, the total area of distribution increases solely through contacts with other potential adopters starting from the place of origin.
The probability of spreading decreases with the spatial distance to the source location.
Relocative diffusion
With relocation diffusion (relocation diffusion), the adopters leave the area of origin and move to new regions, in which they trigger the spread of the innovation. Examples are infectious diseases that break out in several regions almost simultaneously by being quickly relocated to new regions (e.g. by air travelers). This form of diffusion is mostly related to migration processes of different dimensions and range.
The probability of spread is linked to the movement of the adopters.
Combined diffusion
Combined expansion and relocation processes are the most common form of diffusion. Here, propagation processes from a point of origin (contact diffusion) are superimposed on the relocation diffusion due to the displacement of the propagation source.
The spread of foreign workers in the Federal Republic of Germany may serve as an example of the type of combined diffusion process.
In this case, the probability of spreading depends on both the spatial (social) distance to the starting point and the direction of movement of the adopters.
Hierarchical diffusion
It has often been observed that an innovation (e.g. television, cell phone, fax machine, fashion) does not spread evenly, but rather depends on the hierarchical order of a settlement system . This dependency can be seen both in agglomerations and in rural regions.
The spread in a socially structured society often takes the form of a hierarchical diffusion, in that innovations are initially accepted by members of the top social class and gradually seep into the lower classes.
In hierarchical diffusion, the speed of propagation depends on the direction of the spread: while a diffusion process from top to bottom runs relatively quickly, the speed of spread from bottom to top is significantly lower.
application
Knowledge of the mechanisms and spatial effects of diffusion processes is widely used in various specialist disciplines. Epidemiology and market research are representative examples .
See also
literature
- R. Abler, JS Adams, PR Gould: Spatial organization . 1971
- T. Hägerstrand: Innovation diffusion as a spatial process. 1968
- P. Haggett : Geography - A Modern Synthesis . 1991
- T. Reichart: Building blocks of economic geography . 1999