Lancaster (2018) describes two levels of evaluating risk communication: textual-level and socio-cultural-level (p. 248-249). Textual-level evaluations focused on "honing language" - simplifying technical language, improving rhetorical messaging, and making the text more effective at mitigating risk (p. 248-249). This approach suggests that the text-content of a single artifact can provide audiences with the necessary information to safely navigate risky situations (p. 249). However, the socio-cultural-level suggests that researching how communication moves through and between groups is more valuable in evaluation. Specifically, communicators making documents/strategies for workplace use and public use need to consider how communications transform while moving between different groups of people.

Rhetoric and power in the workplace

Highlighting this principle, Lancaster introduces research on the Challenger disaster, examining communicative failures in the days leading up to launch. Carl Herndl, Barbara Fennell, and Carolyn Miller(1991) examined the role of organizational power and its relation to ethos , specifically, 'community standing of the speaker' in the Challenger disaster. The night before launch, an emergency meeting was held to determine whether the launch would proceed. Engineers argued for postponement, considering weather concerns (expected temperature at launch was below the recommended safety range) and their hands-on experience with the O-ring structures which had been reported as prone to malfunction weeks prior. Managers argued from positions of program leadership experience, trying to satisfy public pressure for a successful launch, and a lack of "conclusive data" on cold temperatures as a safety hazard for launch conditions (pp. 300-301). Top engineer Roger Boisjoly made a last ditch effort to convince managers before the meeting ended, but states that he "stopped when I realized I couldn't get anyone to listen" (Herndl et al., 1991).

The engineers and managers differed in what they found to be "argumentatively compelling". The two interested parties engaged in discourse exclusively using two sets of priorities (safety vs success). Engineers were seen as overly cautious and stifling progress in discussions about safety, displaying a misunderstanding of their role in those discussions (to inform on safety concerns). Additionally, disagreement on the strength of the safety data regarding cold weather conditions reflected miscommunication. Boisjoly told the Challenger investigative commission his argument that cold weather was a hazard had the necessary data to justify delaying the launch, but the managers disagreed. This string of failures represents a complete breakdown of risk mitigation strategies, which led to the unsafe conditions on the launch date.

The Challenger disaster exemplifies the ethical responsibilities inherent to communicating risks effectively, and socio-cultural challenges that communicators face in fulfilling those responsibilities (p. 250). Lancaster argues for usability testing in organizational communication, with an ethics of care lens to standardize practices and stabilize rhetorical elements across different workgroups. She calls for risk communication strategies to directly address power discrepancies and explore methods to re-distribute power to the necessary groups in order to ensure safe and communicatively functional work environments (p. 252).

Rhetoric and the public's trust

Similar to the workplace, communicating risks to the public presents rhetorical challenges. Lancaster frames the research in this area as usability-focused (making documents useful for target audiences); Coogan, Cox and Pezzullo, and Youngblood have evaluated risk communication through their rhetorical elements (p. 250-251). Coogan examined the role of "ideographs" in the Chicago Transit Authority's communication with the public between 1976 and 1984, similar to the miscommunications of "conclusive data" during the lead-up to the Challenger disaster. Youngblood offered a framework that targets "rhetorical tensions" in risk communication - seemingly small differences in meanings, as well as in "rhetorical values" between groups that can lead to miscommunication (p. 251). In the case of the Elk River spill, health officials first estimated the spill of MCHM into public water at 2,500 gallons; this figure was revised in the following days to 7,500, then 10,000 gallons. The drastic alterations of the crises' scope in its early stages from health officials undermined public trust in the overall crisis response. A later review concluded that the "nuance" in language of making rough estimates, commonly used in crisis communication, was not conveyed effectively by officials (p. A217).

Trust between parties is an important component of Heidi Larson's (2012) proposed framework for implementing risk communication measures in global vaccine programs to increase participation levels. Larson noted that trust-building activities such as "adopting the mode of vaccine delivery in the program", to accommodate local preferences, increased vaccine uptake (p. 1055). Program designers adapted by having all vaccines in the program be administered by women who were local to the area (Northern Nigeria). Larson acknowledges the benefit of such activities - they introduce collaboration between programs and citizens to build mutual understanding and trust (p. 1057).