is the process through which an innovation is communicated through certain channels over-time among the members of a social system (Rogers, 2003
). For example, Barker (2004)
reports on three international development efforts in relation to diffusion concepts. In Haiti, a United States Agency for International Development effort to conduct HIV prevention education in rural villages identified and recruited village voodoo practitioners, who are almost always considered credible and trusted sources of advice by Haiti villagers, to encourage villagers to participate in village meetings with USAID change agents. Meeting attendance exceeded campaign objectives by 124%. In Nepal, where vitamin A deficiency contributes to very high rates of infant and maternal mortality, the innovation of kitchen gardens was diffused among households through neighbor social modeling, resulting in heightened knowledge, positive attitudes, increased vegetable and fruit growing and consumption, and improvements in vitamin A nutrition. In Mali in 1999, a study of 500 Malian youth evaluated their information-seeking behavior and perceptions of source credibility concerning reproductive health. A lack of accurate knowledge among youth was attributed to their most trusted sources of information being friends and siblings; youth did not consider credible information sources including health agents and teachers to be accessible enough or trustworthy.
Diffusion studies have demonstrated a mathematically consistent sigmoid pattern (the S-shaped curve) of over-time adoption for innovations that are perceived to be consequential by potential adopters, when the decisions to adopt are voluntary, and with attendant logically-related propositions, qualifying this literature as a theory of social change (Green, Gottlieb, & Parcel, 1991
). Many studies have shown a predictable over-time pattern when an innovation spreads, the now familiar S-shaped cumulative adoption curve. The “S” shape is due to the engagement of informal opinion leaders in talking about and modeling the innovation for others to hear about and see (see ).
Figure 1 The generalized cumulative curve that describes the curvilinear process of the diffusion of innovations. For any given consequential innovation, the rate of adoption tends to begin slow, accelerate because of the activation of positive word of mouth communication (more ...)
Key components of diffusion theory are
- The innovation, and especially potential adopter perceptions of its attributes of relative advantage (effectiveness and cost efficiency relative to alternatives), complexity (how simple the innovation is to understand), compatibility (the fit of the innovation to established ways of accomplishing the same goal), observability (the extent to which outcomes can be seen), and trialability (the extent to which the adopter must commit to full adoption);
- The adopter, especially each adopter’s degree of innovativeness (earliness relative to others in adopting the innovation);
- The social system, especially in terms of the structure of the system, its local informal opinion leaders, and potential adopter perception of social pressure to adopt;
- The individual adoption-process, a stage-ordered model of awareness, persuasion, decision, implementation, and continuation;
- The diffusion system, especially an external change agency and its paid change agents who, if well trained, correctly seek out and intervene with the client system’s opinion leaders, paraprofessional aides, and innovation champions.
When social work practitioners themselves are targeted for behavior change, such as to adopt new evidence-based interventions to in turn offer them to populations at risk, then they are potential adopters within a client system.
Diffusion occurs through a combination of (a) the need for individuals to reduce personal uncertainty when presented with new information, and (b) the need for individuals to respond to their perceptions of what specific credible others are thinking and doing, and (c) to general felt social pressure to do as others have done. Uncertainty in response to an innovation typically leads to a search for information and, if the potential adopter believes the innovation to be interesting and with the potential for benefits, a search for evaluative judgments of trusted and respected others (informal opinion leaders). This advice-seeking behavior is a heuristic that allows the decision maker to avoid comprehensive information-seeking, reflecting Herbert Simon’s seminal insight about the importance of everyday constraints in “bounding” the rationality of our decision making (Gigerenzer & Selten, 2001
Needs or motivations differ among people according to their degree of innovativeness (earliness in adoption): The first to adopt (innovators
) tend to do so because of novelty and having little to lose; the next to adopt (early adopters
, including the subset of opinion leaders) do so because of an appraisal of the innovation’s attributes; and the subsequent large majority adopts because others have done so and they come to believe that it is the right thing to do (an imitative effect). These motivations and time of adoption are related to and can be predicted by each adopter’s structural position in the network of relations that tie the social system together (Kerckhoff, Back, & Miller, 1965
Diffusion approaches to spread effective social work programs can focus on the tailoring of messages according to each individual’s stage in the individual-decision process (now more commonly termed the individual’s degree of readiness
or stage of change
), legitimization by high status persons as a cue to attention for others, employment of change agents to interact with potential adopters, advocacy by organizational champions, or the cooperation of informal opinion leaders. When all is said, the promise of the history of diffusion scholarship and diffusion practice is a promise of efficiency
in intervention: Communicating an innovation to a special small subset of potential adopters so that they, in turn, will influence the vast majority of other potential adopters to attend to, consider, adopt, implement, and maintain the use of worthy innovations. Our interventions must be high in reach but low in cost in order to most persuasively demonstrate worth in intervention (Dearing, Maibach, & Buller, 2006
Diffusion paradigm concepts are not new. The French judge cum sociologist Gabriel Tarde explained diffusion as a societal-level phenomenon of social change in his 1902 book, The Laws of Imitation, including the identification of an S-shaped curve in cumulative adoptions over time and the importance of opinion leadership in promulgating that distribution. As a judge, Tarde had taken note of the way people coming before the bench used new slang and wore new clothing fashions as if on cue. In Germany at the same time, Georg Simmel, a political philosopher, was writing about how individual thought and action was structured by the set of interpersonal relations to which a person was subject. Tarde’s perspective was the forerunner for the macro, social system perspective on diffusion as the means by which cultures and societies changed and progressed. Simmel’s contribution explicated in his book, Conflict: The Web of Group Affiliations, was the forerunner for understanding how social network position affects what individuals do in reaction to innovations, and when. Together, these perspectives provided the micro-macro explanation for much about diffusion processes: How system-level effects pressured the individual to adopt new things; and how individuals, linked in social networks, contributed to (and mostly resisted) system change.
Following Tarde and Simmel, European anthropologists seized on diffusion theory as a means to explain the continental drift of people, ideas, means of social organization, and primitive technologies. American anthropologists also conducted historical studies but they confined their analyses to more discrete innovations in smaller social systems such as a community or a region of the country. The studies of these early diffusionists encouraged sociologists to take up diffusion work in contemporary 1920s and 1930s society, focusing on informal communication in friendship or social support networks as an explanation for rural-to-urban migration, the city-to-rural spread of innovations in fashion and language and products, the importance of jurisdictions as barriers to diffusion, and the importance of proximity to the spread of ideas (Katz, Levin, & Hamilton, 1963
The dam broke in 1943 with publication of an article by Bryce Ryan and Neil C. Gross reporting on the diffusion of hybrid seed corn in two American farming communities (Ryan & Gross, 1943
). This seminal article set the paradigm for many hundreds of future diffusion studies by emphasizing individuals as the locus of decision, adoption as the key dependent variable, the key role of a centralized change agency that employed change agents, and the importance of different communication channels for different purposes at different times in the individual innovation-decision process. The Ryan and Gross article propelled diffusion study to center stage among rural sociologists and made the practice of diffusion a primary toolbox in the day-to-day work of agricultural extension agents. Soon, many scholars in general sociology, medical sociology, organizational studies, education, journalism, communication, and public health began diffusion research.
The hottest intellectual concept studied was innovativeness (time of adoption relative to others) and its correlates. These studies often focused on sociodemographics and beliefs, both abiding scholarly interests in larger sociology and marketing research paradigms. Unfortunately, this emphasis steered diffusion scholarship away from the study of interpersonal, group, and relational influence on adoption behavior. This development became most clear in the fascination with innovativeness as a means to understand organization-level diffusion. Many management and organizational scholars conducted correlational studies of organizational innovativeness and a variety of organization-level characteristics (size, market share, bureaucratic structure, industry type, centralization, etcetera), a paradigmatic burst of activity that contributed little to an understanding of diffusion of innovations across organizations. One positive development of this organization-level focus on adoption as a dependent variable of study was general agreement that adoption could mean very little given the political and social machinations inside organizations. Implementation, not the decision to adopt, was the more important process of study, and innovation and reinvention rather than innovativeness of the whole organization the more revealing research focus.
Mathematical modelers who studied diffusion sought to contrast external-to-the-community “broadcast” models of diffusion in which mass media and change agents from afar introduced ideas into communities, with internal-to-the-community “contagion” models of diffusion in which strong friendship ties, weak acquaintance ties, structural equivalence (similarity in network position as a basis for expecting similar adoption behaviors and timing), or proximity accounted for diffusion (Strang & Soule, 1998
Trained as a rural sociologist, Everett Rogers, too, conceptualized rural communities as the social systems of study (Rogers grew up on an Iowa farm watching his father not
adopt innovations, so trying to explain this regressive behavior and in turn perhaps helping to improve farming conditions among poverty-stricken farmers came naturally). Rural sociologists focused on community-level phenomena, on interpersonal networks, and on the boundedness of such social systems. The reference groups of community members functioned as very effective filters and gatekeepers, what the prominent sociologist and early diffusion scholar Elihu Katz (1980)
labeled interpersonal selectivity
. If diffusion is about change and destruction and uncertainty, then interpersonal networks and opinion leaders were about stability, normative influence, and the measured appraisal of new ideas. Understanding the social dynamics of community-level systems was a main objective. The diffusion paradigm offered insight into strategies for community capacity building just as it also illustrated the divisive cumulative process by which the haves increasingly left the have-nots behind (Dearing & Meyer, 2006
), a product of repeated S-shaped “curves” of innovation diffusion among the haves, a social process akin to Robert K. Merton’s (1968)
concept of cumulative advantage
To spread agricultural, public health, and educational innovations—and many innovations were a combination of the three—diffusion systems had to be put into place to interact with rural communities. The 1950s, 1960s, and 1970s were decades of huge growth in U.S. federal capacity and expansionism. Thus the diffusion systems were centralized in both administrative control and substantive expertise. Knowledge flowed from this core to the periphery with the objective of lessening the problems of farmers, social workers, public health officers, and teachers. The main model for these systems was the agricultural Cooperative Extension Service that at the time was heralded for its international successes in crop production increases (the so-called Green Revolution). But the extension service model was expensive. There was not enough money to send change agents to regularly meet with all public health officers and teachers. The agricultural rural sociology lesson about finding and using opinion leaders to influence the decisions of their near-peers got lost at the same time that new information technologies promised so much. Accordingly, some of the dissemination systems that were created looked a lot like clearinghouses of published reports (Hutchinson & Huberman, 1993
So the classical diffusion paradigm found widespread application both among academicians interested in different types of innovations and among practitioners who perceived the paradigm as a means for spreading solutions to real-world problems, yet it was also changed as it was adapted from agriculture to public health and education and as more efficient dissemination possibilities arose. Backlashes against these large investments, partly based in knowledge utilization studies showing little effect on the decisions of practitioners, focused on what seemed to be the advocacy of innovations that were the products of commercial firms. This criticism became particularly acute concerning international development, where the unintended and undesirable consequences of using the new “evidence-based” innovations were at times devastating to human health and the natural environment (McAnany, 1984
; Rogers, 2003
). This broadcast model of diffusion was also put into place without attendant strategy on interpersonal influence, implementation support, or behavioral or organizational maintenance.
Application by government agencies of diffusion concepts was pursued on a large scale but usually only concerned one or two concepts. A support network of change agents would be created, or innovation attributes would be used in the creation of message content, or peer-to-peer communication would be encouraged, or message content would be tailored to a type of individual’s readiness to change, or implementation support would be provided. A notable exception has been the U. S. Cooperative Extension Service which has long applied multiple diffusion concepts in concert to affect change. A contemporary and exceptional example is the Centers for Disease Control and Prevention’s new effort in HIV prevention, the Diffusion of Effective Behavioral Interventions (DEBI) project. This centrally-coordinated federal partnership with state health departments concerns a cluster of evidence-based HIV prevention interventions which 21 are communicated to potential adopters in community-based organizations both in terms of their underlying principles and their manifest components, and which is comprehensively supported throughout the process of organizational implementation through the provision of trainers, capacity-building assistance, marketing assistance, behavioral scientists, and evaluation consultants (Collins, Harshbarger, Sawyer, & Hamdallah, 2006
For every commendable application of diffusion theory concepts that accurately operationalizes certain of the empirical results from the collective of diffusion research, there are many examples of the diffusion literature being operationalized in ways that a diffusion scholar might not recognize. Two examples in this regard are the World Health Organization’s strategy for spreading effective HIV/AIDS treatment and care (World Health Organization [WHO], 2004
), and the Institute for Healthcare Improvement’s model for system-wide change (Massoud et al., 2006
). Both of these commendable efforts developed clear change models that the authors identify as being based in diffusion of innovation theory, yet they do not obviously use prior knowledge from diffusion research about why innovations spread in ways that reflect diffusion research results. Efforts such as these may suggest that there are more ways to affect change than is represented in the diffusion literature; they may also suggest the ease with which the translation of generalized lessons can result in misunderstanding and misapplication. Based solely on my working with the diffusion literature and with organizations that seek to spread evidence-based practices, I list in common ways in which what is done in practice can work against diffusion.
TOP 10 DISSEMINATION MISTAKES