Diffusion of innovations

Diffusion Theory

Diffusion theory is a model that explains how innovation is spread and adopted throughout a society. Adopters of innovation are categorized as innovators, early adopters, early majority, late majority and laggards. The Diffusion of Innovation model was developed by Everett M. Rogers, and uses an S-curve to graph the adoption of an innovation. Diffusion theory is used in many disciplines to explain trends, economic patterns, health and medical concerns and technology innovations. This model is an important part of change management and contains four key elements:

1. . What is the innovation?
2. . How is it communicated?
3. . The idea is transmitted over time
4. . The idea is diffused to members of the society

Adopters of innovation experience five stages of diffusion:

1. Knowledge - awareness of the idea and perceived benefit
2. Persuasion – convinced of the value of the innovation
3. Decision – judgment to adopt the innovation
4. Implementation – enacting the innovation
5. Confirmation - acceptance or rejection of the innovation

The Innovation

New innovations follow a pattern of development. The steps include identifing a need or problem, researching and developing a solution, commercialization of the innovation, and spreading of the new idea. Once an innovation is adopted, certain consequences follow. These consequences are discussed at the bottom.

For any new idea to diffuse effectively there must be a relative advantage for using the new innovation. The innovation must be compatible with existing systems and can not be too complicated. It helps if a user can try the innovation themselves. Ultimately, there must be an improvement from the old way of doing something in order to expect the idea or technology to spread. 22:43, 2 July 2007 (CDT)

The Social System

Opinion Leaders

Opinion Leaders are individuals who lead in influencing the opinions of others. Their behavior is important in determining the rate of adoption of an innovation in a system.

The Hypodermic Needle Model

The Hypodermic Needle Model suggested that mass media had direct, immediate, and powerful effects on a mass audience. Examples included were the Spanish-American War, Joseph Goebbels, and Madison Avenue. The model was ultimately viewed as too simplistic, mechanistic, and too gross to accurately measure the effects of mass media. It also ignored the role of opinion leaders.

The Two-Step Flow Model

The Two-Step Flow Model suggests that communication flows from a source, via mass media channels, to opinion leaders, who in turn pass it on to followers. A study of the 1940 presidential election in Erie County, Ohio discounted the effects of mass media in voting decisions. The first step in this model is a transfer of information from the media to an opinion leader. This is followed by a spread of interpersonal influence. This model does not tell us enough. There are more than just two steps in a flow of communication, but the model focused communication study upon the study of opinion leadership.

Homophily and Heterophily

Homophily is the degree to which pairs of individuals who communicate are similar. The similarities can be things like beliefs, education, socioeconomic status, etc. Communication is generally more effective when source and receiver are homophilous. Heterophily is the degree to which pairs of individuals who interact are different in certain attributes. Heterophilous networks often connect two cliques, thus spanning two sets of socially dissimilar individuals in a system. Homophily accelerates the diffusion process, but limits the spread to those who are closely connected. Ultimately, the diffusion process can occur only through communication links that are at least somewhat heterophilous.

Measuring Opinion Leadership and Network Links

1. The sociometric method consists of asking people whom they sought for information or advice about a given topic. This is usually a highly valid measure of opinion leadership. A large number of respondents is needed to ensure validity.
2. An alternative to using sociometry to identify opinion leaders is to ask key informants who are especially knowledgeable about the networks in a system. This technique is almost as accurate as the sociometric method, but requires fewer respondents.
3. The self-designating technique allows respondents to indicate the degree to which others in the system regard them as influential. This method obviously depends on the accuracy with which respondents can identify and report their images.
4. Opinion leadership can be measured by observation, in which an investigator identifies and records the communication behavior in a system. This method is typically very accurate, but it can be obtrusive. Also, the members of a system who are being observed might act differently because they know they are being observed. This method has not been used often.

When two or three types of opinion leadership measurement have be utilized with the same respondents, positive correlations among the measures have been obtained, although they are not all in total agreement. All four methods have shown to be about equally valid.

Monomorphic and Polymorphic Opinion Leadership

Monomorphism is the degree to which an individual acts as an opinion leader for a single topic.

Polymorphism is the degree to which an individual acts as an opinion leader for a variety of topics. The degree of polymorphic opinion leadership seems to vary with such factors as the diversity of topics which are measured.

Most studies report, more or less, polymorphism to be more prevalent.

Communication Network Analysis

A communication network consists of interconnected individuals who are linked by patterned flows of information. Networks have a certain degree of structure or stability. This patterned aspect of networks provides predictability to human behavior. The communication structure consists of the differentiated elements that can be recognized in the patterned communication flows in a system. This communication structure is so complex that, except in very small systems, most members are not even aware of the overall structure of which they are a part.

In order to calculate the number of possible network links, we use the formula N(N-1)/2 where N is the number of individuals in a system.

• Social distance refers to the degree to which an individual perceives a lack of intimacy with individuals who differ in socioeconomic status, ethnicity, and other variables.
• Communication proximity is the degree to which two linked individuals in a network have personal communication networks that overlap.
• A personal communication network consists of the individuals who are linked by patterned communication flows to a given individual.
• Some personal networks consist of a set of individuals, all of whom interact with each other; these are interlocking personal networks.
• In contrast, a radial personal network consists of a set of individuals who are linked to a focal individual but do not interact with each other.

The Strength-of-Weak-Ties Theory

An individual’s close friends or colleagues seldom know much than the individual does not also know. Such an ingrown system is not effective for catching new information. Weak ties are often referred to as bridge links, which are defined as an individual who connects two or more cliques.

Social Learning Theory

The central idea of social learning theory is that one individual learns from another by means of observational modeling. The observer’s behavior is not exactly the same as the model’s, which would be simple imitation of blind mimicry. Rather, in social modeling the observer extracts the essential elements from an observed behavior pattern in order to perform a similar behavior.

Critical Mass

The notion of critical mass originated in physics, where it was defined as the amount of radioactive material necessary to produce a nuclear reaction. For us, we will define critical mass as the point after which further diffusion becomes self-sustaining. Rogers presents telephones, fax machines, and the Internet as good examples (pp. 343-348).

Another concept related to critical mass is network externalities, which is defined as the quality of certain goods and services such that they become available to a user as the number of users increases. The growth of the Internet was slowed in the early stages of diffusion by this.

Cell phones did not suffer this problem since they were connected to the large existing number of land line phones.

Critical mass can also affect the discontinuance of an interactive innovation. Discontinuance of an interactive innovation by one individual may lead eventually to a critical mass of discontinuers, and then perhaps to complete rejection. For example, if an individual stops using E-mail and other follow suit.

All adopters are not equal in their influence in a critical mass situation. A small number of highly influential individuals who adopt a new idea may represent a much stronger critical mass than an equally sized number of individual adopters who have little influence.

Individual Thresholds for Adoption

A threshold is the number of individuals who must be engaged in an activity before a given individual will join that activity. Note that threshold occurs at the individual level, whereas critical mass operates at the system level.

Why Do Individuals Adopt Prior to Critical Mass?

Innovators who rush to adopt an innovation first have a very low threshold for adoption, due to their high degree of venturesomeness. Later adopters have higher thresholds. Threshold levels are normally distributed, thus creating the S-curve of diffusion.

Networks and the Turbocharger Effect

This is the additional variance in a dependent variable well beyond the direct effects of the individual-level variables. Adding network variables to individual-level variables such as education and socioeconomic status can help to explain an increase in diffusion.

Consequences of Diffusion

Many innovations cause both negative and positive consequences. The adoption of new ideas within a social system can produce desirable or undesireable changes. Some changes have direct or indirect consequences. While others cause anticipated or unanticipated consequences. The main purpose of diffusion is to maintain dynamic equilibrium which is the ability to cope with the amount of change that is being diffused. 22:26, 2 July 2007 (CDT)

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References
Rogers, E.(2003). Diffusion of Innovations, 5th Edition. New York: Free Press.
Brown, Lawrence A.(1981). Innovation Diffusion: A New Perspective.Methuen, NY.