The document discusses key concepts from Everett Rogers' book Diffusion of Innovations including: 1) Diffusion is the process by which an innovation is communicated over time through certain channels among members of a social system. The main elements are the innovation, communication channels, time, and the social system. 2) Innovations have perceived attributes like relative advantage and complexity that influence their rate of adoption. Communication channels and opinion leaders also impact diffusion. 3) Diffusion research traditions developed across various fields and focused on topics like the rate of adoption, innovativeness, and consequences of innovations.

1. Diffusion of Innovations by Everett Rogers, 2003 Chapter 1: Elements of Diffusion What is Diffusion? It is the processing which an innovation is communicated through certain channels over time among the members of a social system. o A special type of communication; about a new idea Communication is a process in which participants create and share information with one another in order to reach a mutual understanding. o A convergence or divergence; a two-way street New ideas cause o Uncertainty: the degree to which a number of alternatives are perceived with respect to the occurrence of an event and their reliability To replace uncertainty o Information: difference in matter-energy that affects uncertainty in a situation where a choice exists among a set of alternatives Innovation is a kind of social change o Social Change: the process by which alteration occurs in the structure and function of a social system

2. Four Main Elements in the Diffusion of Innovations o The Innovation: an idea, practice, or object perceived as new by an individual or other unit of adoption; not necessarily new o Technological Innovations, Information and Uncertainty Technology: a design for an instrumental action that reduces the uncertainty in the cause/effect relationship involved in achieving a desired outcome Two Components Hardware: physical object Software: information o Technology Clusters: one or more distinguishable elements of technology that are perceived as being close interrelated o Perceived Attributes of innovations Relative Advantage: the degree to which an innovation is perceived as better than the idea it supercedes Compatibility: the degree to which an innovation is perceived as being consistent with existing values, past experiences, and needs of potential adopters Complexity: the degree to which an innovation is perceived as difficult to understand and use Trialability: the degree to which an innovation may be experimented with on a limited basis Observability: the degree to which the results of an innovation are visible to others o Re-invention: the degree to which an innovation is changed or modified by the user in the process of adoption and implementation

3. Communication Channels o The means by which messages get from one individual to another o Mass Media Channels: all those means of transmitting messages that involved a mass medium that enable a few to reach an audience of many o Interpersonal Channels: involved a face to face communication between two parties o Heterophily and Diffusion Homophily: the degree to which two or more individuals who interact are similar in certain attributes Heterophily: opposite of above; “differ” Heterophily causes problems for diffusion of innovations; most people are heterophilous

4. Time o The Innovative-Decision Process: the process in which an individual passes from first knowledge of an innovation, to a formation of an attitude toward it, to a decision to accept or reject it, to implementation and use of the new idea and to confirmation of this decision Knowledge: gained when an individual learns of the innovation’s existence ad gains some understanding of how it functions Persuasion: when an individual forms a favorable or unfavorable attitude toward the innovation Implementation: when an individual puts an innovation to use Re-invention is most likely to occur here Confirmation: when an individual seeks reinforcement on an innovative-decision that has already been made Steps lead to Adoption: decision to make full use of an innovation as the best course of action Rejection: a decision not to adopt an innovation Discontinuance: a decision to reject the innovation after the adoption Innovation Decision Period: length of time required to pass through the innovation decision process o Innovativeness and Adopter Categories Innovativeness: the degree to which an individual or other unit of adoption is relatively earlier in adopting new ideas than the other members of a system Adopter Categories: the classification of members of a social system on the basis of innovativeness  Innovators  Early Adopters  Early Majority  Late Majority  Laggards Rate of Adoption: the relative speed with which an innovation is adopted by members of a social system Most innovations have S-shaped curves for adoption

5. Social System: a set of interrelated units that are engaged in joint problem solving to accomplish a common goal Social Structure and Diffusion Structure: the patterned arrangements of the units in a system; type of information that decreases uncertainty Communication Structure: the differentiated elements that can be recognized in the patterned communication flows in a system System Effects: the influences of the structure and/or composition of a system on the behavior of the members of the system System Norms and Diffusion Norms: the established behavior patterns for the members of a social system Opinion Leaders and Change Agents Opinion Leadership: the degree to which an individual is able to influence other individuals’ attitudes or overt behavior informally in a desired way with relative frequency Communication Network: interconnected individuals who are linked by pattern flows of information Change Agent: an individual who influences clients’ innovation decisions in a direction deemed desirable by a change agency Aide: less than fully professional change agent who intensively contacts clients to influence their innovation decisions

6. Types of Innovation-Decisions Optional: choices to adopt or reject that are made by an individual independent of the decisions of the other members of the system Collective: choices to adopt or reject that are made by consensus among the members of the system Authority: choices to adopt or reject that are made by a relatively few individuals in a system who possesses power, status, or technical expertise Contingent: choices to adopt or reject that can be made only after a prior innovation-decision Consequences of Innovations Consequences: the changes that occur to an individual or social system as a result of the adoption or rejection of an innovation Desirable vs. Undesirable Direct vs. Indirect Anticipated vs. Unanticipated

7. Chapter 2: A History of Diffusion Research Research Traditions: a series of investigations on a similar topic in chich successive studios are influenced by preceeding inquiries Roots and Traditions Gabriel Tarde and Imitation Gerog Simmel: Strangers British and German-Austrian Diffusionists

8. Diffusionist Research Traditions Invisible College: the informal network of researchers who form around an intellectual paradigm to study a common topic Traditions Anthropology Participant Observation: attempt by researcher to adopt the perspective of respondents by sharing their day-to-day experiences Early Sociology Rural Sociology Education Public Health and Medical Sociology Communication Salience: the degree to which a news event is perceived as important by individuals Marketing and Management Audience Segmentation Formative Research Positioning Price Utilization of Communication Channels Geography General Sociology Other Traditions

9. Typology of Diffusion Research o Earliness of Knowing About Innovations o Rate of Adoption of Different Innovations in a Social System o Innovativeness o Opinion Leadership o Diffusion Networks o Rate of Adoption in Different Social Systems o Communication Channel Usage o Consequences of Innovation