Blockchain is an emerging infrastructural technology that is proposed to fundamentally transform the ways in which people transact, trust, collaborate, organize and identify themselves. In this paper, we construct a typology of emerging blockchain applications, consider the domains in which they are applied, and identify distinguishing features of this new technology. We argue that there is a unique role for the HCI community in linking the design and application of blockchain technology towards lived experience and the articulation of human values. In particular, we note how the accounting of transactions, a trust in immutable code and algorithms, and the leveraging of distributed crowds and publics around vast interoperable databases all relate to longstanding issues of importance for the field. We conclude by highlighting core conceptual and methodological challenges for HCI researchers beginning to work with blockchain and distributed ledger technologies.

There is a widespread belief that pervasive technologies will encourage and facilitate partnerships between citizens and civic authorities, enabling individuals to play a greater role in civic planning, service delivery and infrastructure management. However, at present sustained use and perceived value of civic engagement technologies remains low because the design space is poorly understood by system developers who focus almost exclusively on empowering citizens rather than adopting an informed, inclusive approach that addresses the needs of both citizens and civic authorities, and helps establish trusted relationships between these different stakeholders. We report on an extensive study of civic engagement in the domain of public infrastructure maintenance and provide insights into the civic management processes to support future design of trusted civic engagement interactions.

BACKGROUNDWalking school buses (WSBs) offer a potentially healthier way for children to get to school while reducing traffic congestion. A number of pressing societal challenges make it timely to evaluate evidence of their value.METHODSStudies that focused solely on WSBs were identified through online and manual literature searches. Twelve WSB studies involving a total of 9169 children were reviewed. Study aims, designs, methods, outcomes, and barriers and facilitators were examined.RESULTS WSBs were found to be associated with increased prevalence of walking to school and general activity levels although not always significantly. Time constraints emerged as barriers to WSBs, impacting on recruitment of volunteers and children to the WSBs. Facilitators of WSBs included children enjoying socializing and interacting with the environment.CONCLUSIONSPreliminary evidence of the health value of WSBs was demonstrated, along with recommendations for the design of future studies. By tackling barriers of time constraints, volunteer recruitment, and parents' safety concerns while at the same time, increasing convenience and time savings for families, future WSBs are likely to be more sustainable and taken up by more schools. Implications for future innovation in school health were identified.

Driven by changes in working practices and technology trends, organizations are increasingly reliant on mobile workers and the data they capture. However, while significant work has been carried out on increasing the usability of mobile devices and applications, little attention has been paid to the quality of data captured by mobile workers. If this data is inaccurate or untrustworthy, serious consequences can ensue. In this paper we study a system targeted at mobile workers in the highways sector that is deliberately designed to increase the accuracy and trustworthiness of the data collected. The resulting Inspections application has been very positively received by workers and we present lessons that we believe can be applied to other applications of this type.

HighlightsNovel smartphone presentation of experimentally-controlled word lists.Strong temporal contiguity effects in free recall at rates of 1 word per hour.Shallow serial position effects in free recall at rates of 1 word per hour.Shallow primacy effects in serial recall at rates of 1 word per hour.Recency in recognition of experimental words presented over 50 days.