Aspects of the research and practice paradigm known as the diffusion of innovations are applicable to the complex context of health care, for both explanatory and interventionist purposes. This article answers the question, "What is diffusion?" by identifying the parameters of diffusion processes: what they are, how they operate, and why worthy innovations in health care do not spread more rapidly. We clarify how the diffusion of innovations is related to processes of dissemination and implementation, sustainability, improvement activity, and scale-up, and we suggest the diffusion principles that can be readily used in the design of interventions.

Consumers increasingly rely on online product reviews when making purchase decisions. However, assessing the credibility of online reviewers presents consumers with unique challenges. This paper examines how consumer perceptions of reviewer credibility are influenced by the presence and type of textual errors in the review itself. The results of an online experiment indicate that consumers' reactions to textual errors are moderated by their general trust in others. Low-trust consumers are relatively insensitive to textual errors in judging reviewer credibility. However, high-trust consumers are less forgiving of typographical errors (which may signal carelessness) than orthographical errors (which may indicate cognitive challenges). Implications for future research are discussed.

Building on the network theory of brokerage and closure, this study takes a structural approach to examine network structure and its influence on reception of different types of social support. The study extracted ego networks of 227 active users from a large online health social network and tracked their received supportive comments on personal profiles for 3 months. A total of 3,270 comments were analyzed. The results showed that network brokerage (operationalized as effective size) predicted the amount of informational and network support, whereas network closure (operationalized as local clustering coefficient) predicted the amount of emotional and esteem support received on one's profile. Moreover, brokerage was found to predict received emotional support. Theoretical and practical implications were discussed.

Community engagement is a vital aspect of addressing environmental contamination and remediation. In the United States, the Superfund Research Program (SRP) forms groups of academic researchers from the social and physical sciences into Community Engagement Cores (CECs) and Research Translation Cores (RTCs), which focus on various aspects of informing and working with communities during and through the resolution of environmental crises. While this work typically involves engaging directly with members of affected communities, no two situations are the same. In some cases, alternative approaches to community engagement can be more appropriate for community improvement than traditional approaches. In particular, when research teams become involved in contamination crises at a late point in the process, their contributions can be better directed at supporting and reinforcing the work of institutional stakeholders charged with remediating pollution. Relevant factors include issue fatigue among a local population, and contamination that is due to a major employer. Supported by literature and experience, we offer several propositions that we believe lay out conditions that warrant such an approach by academic teams, rather than their direct engagement with unaffiliated individuals in communities.

Trust is generally recognized as important for risk-relevant behavior but research suggests that trust in different organizations may have varying effects. This research advances the literature by testing two hypotheses which postulate that this variability can be explained by risk perception. We collected data from 351 anglers regarding their trust in nine organizations whose efforts are relevant to dioxin contamination in Michigan's Saginaw Bay Watershed, risk perceptions, and self-reports of risky behavior (i.e., consumption of local fish identified as especially likely to contain contaminants). As hypothesized (H1), the negative effect of trust in two agencies-the Michigan Department of Natural Resources (MDNR) and a Michigan Department of Health and Human Services-sponsored River Walker Program (RWP)-on risky behavior was significantly mediated by risk perception but these effects differed from each other such that trust in the MDNR was associated with increased perceptions of risk while trust in the RWP was associated with decreased perceptions of benefit. Also as hypothesized (H2), the positive effect of trust in Dow Chemical Company on risky behavior was significantly mediated by risk perception such that increased trust in Dow was associated with reduced risk perception. The current results lend credence to arguments regarding the importance of specificity in the target of trust and advance this literature by suggesting that differential effects on risk perception help explain this variability.