Collective action within an environment of unknown unknowns: Experiences with the port of Mars Game.

There is limited research about how groups solve collective action problems in uncertain environments, especially if groups are confronted with unknown unknowns. We aim to develop a more comprehensive view of the characteristics that allow both groups and individuals to navigate such issues more effectively. In this article, we present the results of a new online experiment where individuals make decisions of whether to contribute to the group or pursue self-interest in an environment with high uncertainty, including unknown unknowns. The behavioral game, Port of Mars is framed as a first-generation habitat on Mars where participants have to make decisions on how much to invest in the shared infrastructure to maintain system health and how much to invest in personal goals. Participants can chat during the game, and take surveys before and after the game in order to measure personality attributes and observations from the game. Initial results suggest that a higher average social value orientation and more communication are the key factors that explain why some groups are more successful than others in surviving Port of Mars. Neither other attributes of players nor the group's communication content explain the observed differences between groups.

Proposal and practicality of an alternative blue-light hazard risk assessment method for high-intensity white-light sources at workplaces.

Objectives. It is prescribed to determine blue-light hazard (BLH) weighted radiances, LB, for an assessment of spotlights with an angular subtense α≥11mrad. The BLH weighted irradiance, EB, can be used alternatively for smaller sources. Appropriate instruments are not common among persons commissioned with risk assessment (RA), and especially LB measurements may be challenging. Therefore, a practical BLH RA approach is proposed that is based on illuminance, Ev, pre-calculated blackbody BLH efficacies of luminous radiation, KB,vPlanck, and solid angle considerations. Methods. The practicality of this method was examined and compared against other RA approaches. Results. To ensure comparability of the applied instruments, measurements were performed close to a radiance standard, showing deviations within the lamp's expanded uncertainties (<4%), whereas the deviations were ±15% for longer distances. Focusing on a complex light-emitting diode (LED) spotlight, all detected values could be converted to LB by means of the RA methods within ±20%. Two field tests with several spotlights yielded maximum permissible exposure durations (MPED) obtained from the different RA approaches that agreed among each other within uncertainties largely below ±30%. Conclusion. The general practicality of the proposed Ev method can be concluded for a workplace BLH RA of white-light sources.