|
|
|
|
|
A. Differentiate between relocation diffusion and expansion diffusion by referring to the "number of adopters".ANSWER:Relocation diffusion is a process in which items being diffused leave the originating areas as they move to new areas, i.e., the items diffuse with people migrating. "Although cultural traits are carried with the people who move, the number of adopters stays the same—at least initially." (p. 63)
Expansion diffusions is a process in which the items being diffused remain and often intensify in the origin area as new areas are being affected, i.e., the items diffuse from person to person. "In this case, the number of people adopting the item expands." (p. 63)
B. Give example of relocation diffusion and expansion diffusion.
ANSWER: "Relocation diffusion is often followed by expansion diffusion, depending partly on how much the new residents interact with the preexisting population. Tacos and pizza are two classic examples of culinary innovations that came to America via relocation diffusion and then spread beyond Mexican and Italian immigrant populations by expansion." (p. 63)AIDS reached the large cities of the US via relocation diffusion when people with the disease settled in these cities. Before the disease spread the number of people with AIDS did not change, just the location of the people with the disease changes. Then, when the disease began to spread from these people to others. This is expansion diffusion and the number of people with the disease increased.
C. Does the S-curve apply to relocation diffusion or to expansion diffusion?
ANSWER: Since the number of people who adopt the innovation increases as we move up the S-curve from left to right, this is expansion diffusion.
[top]
Differentiate between the contagious effects of diffusion and the hierarchical effects. Give examples of each and explain the rationale for each (why do they exist?). Which of the following figures illustrates the contagious effects of diffusion and which illustrates the hierarchical effects (To enlarge: right click on the image and select "View Image")?
|
|
|
|
|
|
|
HIERARCHICAL EFFECTS OF DIFFUSION |
CONTAGIOUS EFFECTS OF DIFFUSION |
ANSWER:Contagious effects refers to the diffusion of a disease, cultural trait, idea, or innovation that spreads outward from a node or epicenter in wave-like fashion. Spatially contagious diffusion emphasizes the frictional force of distance in explaining the spread of things in time and space.
Hierarchical effects refers to the diffusion of a disease, cultural trait, idea, or innovation from larger to smaller places, leaping over nearby but small places in the early stages. Hierarchical diffusion emphasizes the size distribution of urban places (i.e., the urban hierarchy) in explaining the spread of things over time and space.
With the contagious effect places near the origin are usually affected first. "The farther you are from the point or points of origin, the later you will be affected. Think of a pebble tossed in a pond. The ripple spreading through the water is akin to the contagious effect in diffusion. This process is strongly influenced by distance because you are more likely to come in contact with nearby persons than with more remote persons. The spread of Islam from its birthplace in Mecca in what is now Saudi Arabia is a good example of contagious diffusion at work.New clothing and music fads, for example, spread quickly among major world cities like New York, Los Angeles, London, Paris, and Tokyo. Only later do they filter down the urban hierarchy, in other words, down from large cities to smaller places This occurs for several reasons.
First, larger places have a greater potential for interaction. There is far more travel and contact between large cities, in part, due to their complex air, road, and communication links, than between smaller cities. With more carriers of ideas coming to a place, large cities have more interactions with other people and places and, therefore, are first to find out about new styles and trends.
Second, the people in larger cities tend to be more diverse, wealthier, and more accustomed to change; cities attract more risk-taking persons.
Third, the same can be said for the industries in larger cities: they also tend to be more diverse and more able and willing to adopt new technologies and practices.
A classic example of hierarchical diffusion is the spread of radio broadcasting in the “Roaring 20s.” From an initial set of cities (Pittsburgh, Detroit, L.A., Seattle, and Oklahoma City) in 1920, radio diffused to a total of 126 small, medium, and large cities by 1924." (pp. 64-65)
[top]
A. The concept of distance decay applies to which of the following: the contagious effects of diffusion or the hierarchical effects? ANSWER: CONTAGIOUS EFFECTS.
B. Give some examples of distance decay in your life. EXPLAIN. (For example, think of the locations of where have bought gasoline in the last month. Is there any relationship between how often you go to a certain gas station and how far it is from your home?)
ANSWER: I most often buy gasoline at the local gas station just a few blocks from my home. sometimes I buy gas in a nearby town on my way to ski in southern Wisconsin.I buy milk quite often at our new local grocery store ("Wonder Foods"). We also buy milk at the Dominick's supermarket about five miles from my home. I THINK we buy slightly more milk at Wonder Foods.
Our general shopping patterns also show signs of distance decay. We most often shop in McHenry, five miles for our home. Quite often we go to Crystal Lake, about ten miles from home. A few times a year we go to the Spring Hill Mall about 30 miles from home. And, about once a year we go the the Woodfield Mall which is about fifty miles from where we live.
Where do you go out to eat? How often do you go to a close restaurant? How often do you go to a restaurant much further away?
[top]
Discuss examples of the following with regards to the diffusion of AIDS in the United States
ANSWER:
[top]
Use the two maps below to identify any barriers to the diffusion of AIDS in the US and pathways supporting it. (To enlarge: right click on the image and select "View Image")
ANSWER AIDS seems not to spread into more remote areas such as the upper Rocky Mountain west. So this remoteness and sparse population acts a a barrier to the spread of AIDS
Areas with larger cities such as the Northeast, southern California, and finally the southeast have served as pathways for the disease. Note: some students may answer that the spread of AIDS has tended to follow along the coasts. This is a refection of the fact that many large cities in the U.S. are located near coasts.:
[top]
E-Mail instructor: mhealy@harper.cc.il.us
Office: J-262, 847-925-6352
Home: 815-728-1571
