We investigate the development of scientific content knowledge of volunteers participating in online citizen science projects in the Zooniverse (http://www.zooniverse.org). We use econometric methods to test how measures of project participation relate to success in a science quiz, controlling for factors known to correlate with scientific knowledge. Citizen scientists believe they are learning about both the content and processes of science through their participation. We don't directly test the latter, but we find evidence to support the former — that more actively engaged participants perform better in a project-specific science knowledge quiz, even after controlling for their general science knowledge. We interpret this as evidence of learning of science content inspired by participation in online citizen science.

The prevalent lack of research on the interrelations between science, research and popular culture led to the organization of the first International Conference on Science and Research in Popular Culture #POPSCI2015, which took place at Alpen-Adria-Universität in Klagenfurt, Austria, from 17--18 September 2015. The aim of the conference was to bring together not only science communication researchers with an interest in popular culture, but also other scholars, scientists and researchers, artists, media professionals and members from the general public. In this issue of JCOM we present four invited commentaries which are all based on presentations at the conference.

As a result of the large number of media used and a variety of objectives pursued by the various Public Communication of Science (PCS) activities, their evaluation turns into a daunting task. Therefore, a general taxonomy for all the approaches used by PCS could be helpful in order to differentiate their effects and to measure their results. A general format is proposed for a fast and easy evaluation of PCS efforts and to share a common language with all science communicators, who need to easily compare the results of this growing activity.

In recent years, citizen science has gained popularity not only in the scientific community but also with the general public. The potential it projects in fostering an open and participatory approach to science, decreasing the distance between science and society, and contributing to the wider goal of an inclusive society is being explored by scientists, science communicators, educators, policy makers and related stakeholders. The public's participation in citizen science projects is still often reduced to data gathering and data manipulation such as classification of data. However, the citizen science landscape is much broader and diverse, inter alia due to the participation opportunities offered by latest ICT. The emergence of new forms of collaboration and grassroots initiatives is currently being experienced. In an open consultation process that led to the "White Paper on Citizen Science for Europe", the support of a wide range of project types and innovative forms of participation in science was requested. In this paper we argue for mechanisms that encourage a variety of approaches, promote emerging and creative concepts and widen the perspectives for social innovation.

The academic journal paper has been around for several hundred years and during that time has seen shifts in style and structure. This editorial explores the traditional research paper and considers whether thinking about the research paper as a story, provides insights into style and structure that would make research both more transparent and more readable.

Non-invasive prenatal testing (NIPT) is an emerging technology for detecting chromosomal disorders in the fetus and mass media may have an impact on shaping the public understanding of its promise and challenges. We conducted a content analysis of 173 news reports to examine how NIPT was portrayed in English-language media sources between January 1 and December 31, 2013. Our analysis has shown that media emphasized the benefits and readiness of the technology, while overlooking uncertainty associated with its clinical use. Ethical concerns were rarely addressed in the news stories, which points to an important dimension missing in the media discourse.

Interviews were conducted with 110 marine users to elicit their salient beliefs about recording marine species in a citizen science project. The results showed that many interviewees believe participation would increase knowledge (either scientific, the community's, or their own). While almost half of the interviewees saw no negative outcomes, a small number expressed concerns about targeting of marine species by others, or restrictions on public access to marine sites. Most of the people surveyed (n = 106) emphasised the importance of well-designed technological interfaces to assist their data collection, without which they would be unlikely to engage in the project.

Mirror neurons (MN) — or neurons said to be able to "mirror" the sensed environment — have been widely popularized and referenced across many academic fields. Yet, MNs have also been the subject of considerable debate in the neurosciences. Using a criterion based sampling method and a citation analysis, this paper examines the extent of engagement with the neuroscience literature about MNs, looking specifically at the frequency of "MN debate sources" within articles published in the JSTOR and Communication and Mass Media (CMMC) databases. After reporting the results, the paper reviews characteristic examples in context and, ultimately, shows that MN debates remain largely absent from peer-reviewed articles published in JSTOR and CMMC. However, the paper suggests that this happens for good reason and that MNs retain the potential for inventive animations even though debates have gone largely unrecognized.

Whereas the evolution of snow cover across forested mountain watersheds is difficult to predict or model accurately, the presence or absence of snow cover is easily observable and these observations contribute to improved snow models. We engaged citizen scientists to collect observations of the timing of distributed snow disappearance over three snow seasons across the Pacific Northwest, U.S.A. . The primary goal of the project was to build a more spatially robust dataset documenting the influence of forest cover on the timing of snow disappearance, and public outreach was a secondary goal. Each year's effort utilized a different strategy, building on the lessons of the previous year. We began by soliciting our professional networks to contribute observations via electronic or paper forms, moved to a public outreach effort to collect geotagged photographs, and finally settled on close collaboration with an outdoor science school that was well-positioned to collect the needed data. Whereas the outreach efforts garnered abundant enthusiasm and publicity, the resulting datasets were sparse. In contrast, direct collaboration with an outdoor science school that was already sending students to make weekly snow observations proved fruitful in both data collection and educational outreach. From a data collection standpoint, the shift to an educational collaboration was successful because it essentially traded wide spatial coverage combined with sparse temporal coverage for dense temporal coverage at a single, but important location. From a public engagement standpoint, the partnership allowed for more intensive participation by more people and enhanced the science curriculum at the collaborating school.

Citizen Science is part of a broader reconfiguration of the relationship between science and the public in the digital age: Knowledge production and the reception of scientific knowledge are becoming increasingly socially inclusive. We argue that the digital revolution brings the "problem of extension" — identified by Collins and Evans in the context of science and technology governance — now closer to the core of scientific practice. In order to grasp the implications of the inclusion of non-experts in science, the aim of this contribution is to define a role-set of non-certified knowledge production and reception, serving as a heuristic instrument for empirical clarifications.