25 Years of Self-organized Criticality: Concepts and Controversies

Introduced by the late Per Bak and his colleagues, self-organized criticality (SOC) has been one of the most stimulating concepts to come out of statistical mechanics and condensed matter theory in the last few decades, and has played a significant role in the development of complexity science. SOC, and more generally fractals and power laws, have attracted much comment, ranging from the very positive to the polemical. The other papers (Aschwanden et al. in Space Sci. Rev., 2014, this issue; McAteer et al. in Space Sci. Rev., 2015, this issue; Sharma et al. in Space Sci. Rev. 2015, in preparation) in this special issue showcase the considerable body of observations in solar, magnetospheric and fusion plasma inspired by the SOC idea, and expose the fertile role the new paradigm has played in approaches to modeling and understanding multiscale plasma instabilities. This very broad impact, and the necessary process of adapting a scientific hypothesis to the conditions of a given physical system, has meant that SOC as studied in these fields has sometimes differed significantly from the definition originally given by its creators. In Bak’s own field of theoretical physics there are significant observational and theoretical open questions, even 25 years on (Pruessner 2012). One aim of the present review is to address the dichotomy between the great reception SOC has received in some areas, and its shortcomings, as they became manifest in the controversies it triggered. Our article tries to clear up what we think are misunderstandings of SOC in fields more remote from its origins in statistical mechanics, condensed matter and dynamical systems by revisiting Bak, Tang and Wiesenfeld’s original papers

How audience and disclosure characteristics influence memory of sponsorship disclosures

The proliferation of sponsored content (e.g., product placement) in television programmes has been a cause of concern as it may violate the right of consumers to know that a message is sponsored. Therefore, new regulations obligate broadcasters to disclose sponsored content. To achieve its goal of informing the consumer, a sponsorship disclosure must be effectively communicated. This study explores how audience and disclosure characteristics influence memory of sponsorship disclosures. Results show that a disclosure at the beginning of a programme results in less disclosure memory compared to a disclosure in the middle or at the end of a programme. The duration of the disclosure does not directly influence disclosure memory, but a disclosure is best remembered when it is displayed longer and viewers are familiar with the programme. Additionally, viewers' programme and disclosure familiarity increase the chance that a disclosure is remembered, while programme involvement decreases disclosure memory. These results contribute to advertising theory and may be useful in the development of effective sponsorship disclosures, as they indicate several conditions under which disclosures are more likely to be remembered

THE AMBITIONS OF POLICY DESIGN

There is no shortage of warnings concerning the hazards of excessive ambition in consciously-pursued public policy. In the light of these cautions, this paper considers the appropriate ambitions for policy design. The critics have missed the target. There is no need to fear ambition in policy design, provided that openness in communications about policy is secured. Copyright 1988 by The Policy Studies Organization.

Rationality and the Shoulds

This paper is about rational and irrational uses of deontological words, such as "should", "ought", and "must", referred to as "the shoulds". Rationality is taken as a mutual relationship between conceptual schemes and human agency. These are expressed in what Bakhtin referred to as authoritative discourse and internally persuasive discourse respectively. When the conceptual scheme is in place and its authority transparent, and there is interplay between authoritative discourse and internally persuasive discourse, then the shoulds are perceived as rational. When the interplay is disrupted or suppressed the shoulds are seen as irrational. Breakdown occurs in two main ways. First, when the effective conceptual schemes are hidden, and the origin of the shoulds obscured. We describe some instances of the latter, from philosophy, psychotherapy, and experimental studies of rationality. Second, in technology and science the mutual relationship sometimes breaks down because authoritative discourse is too powerful, and inhibits the interplay in order to maintain itself. After describing these pathologies, we turn to William James, who drew attention to a repair kit for rationality in his detection of the psychologist's fallacy. Describing the work of Dewey and Husserl as elaborations of this, we distinguished two essential aspects of rationality, disciplinary expressed in authoritative discourse, and emancipatory expressed in internally persuasive discourse