Differentially Private SQL with Bounded User Contribution

Differential privacy (DP) provides formal guarantees that the output of a database query does not reveal too much information about any individual present in the database. While many differentially private algorithms have been proposed in the scientific literature, there are only a few end-to-end implementations of differentially private query engines. Crucially, existing systems assume that each individual is associated with at most one database record, which is unrealistic in practice. We propose a generic and scalable method to perform differentially private aggregations on databases, even when individuals can each be associated with arbitrarily many rows. We express this method as an operator in relational algebra, and implement it in an SQL engine. To validate this system, we test the utility of typical queries on industry benchmarks, and verify its correctness with a stochastic test framework we developed. We highlight the promises and pitfalls learned when deploying such a system in practice, and we publish its core components as open-source software.

Exploring the impact of game framing and task framing on user participation in citizen science projects

Purpose The purpose of this paper is to examine how game framing and task framing influence experienced meaningfulness (eudaimonia) and perceived enjoyment (hedonia), which, in turn, can account for user participation behavior in citizen science projects. Design/methodology/approach The authors designed and implemented a citizen science system, Citizen Sort, and used a survey method to investigate to what extent game framing and task framing influence participation behavior. PLS–SEM was used to test research hypotheses with 76 Citizen Sort participants. Findings Analysis confirmed that game framing and task framing have a significant impact on perceived enjoyment, but showed that only task framing has a direct effect on experienced meaningfulness. The effects of experienced meaningfulness on participation were fully mediated by perceived enjoyment. Content analysis of qualitative data revealed additional insights. Research limitations/implications This research is limited due to its sample size and considered as an exploratory study, in which PLS–SEM was used to identify the impact of game framing and task framing as well as support the theory development regarding the dual nature of citizen science games. Practical implications This research provided suggestions for scientists, designers and project initiators that game framing and task framing should be effectively integrated to provide enjoyable and meaningful experiences so as to promote user contribution. Originality/value This research is one of initial studies which explored the impact of dual nature of citizen science games. The findings of this study provide the groundwork for guidelines and strategies to facilitate user contribution in citizen science projects.

User recognition mechanism and user contribution behavior in enterprise-hosted online product innovation communities

Purpose This paper aims to conceptualize two patterns of user recognition mechanisms and two kinds of user contribution behavior in enterprise-hosted online product innovation community and explain their relationships between user recognition mechanisms and user contribution behavior of online product innovation community. Design/methodology/approach A Chinese enterprise-hosted online innovation community and an American enterprise-hosted online innovation community are selected as research objects. Four Logit models are developed and some hypotheses are supposed from the perspective of prosocial behavior theory. Objective user data with three months from two online product innovation communities are collected to test with Logit regression analysis. Findings Findings show that there are obvious correlations between user recognition mechanisms and user contribution behavior, and there is also an obvious difference in community user activity level between the quantity-based user recognition mechanism community and the quality-based user recognition mechanism community. More specifically, in the online product innovation community with quantity-based recognition mechanism, both variables of peer recognition and community image motivation significantly affect user proactive contribution behavior. In the online product innovation community with quality-based recognition mechanism, the variable of peer recognition significantly affects both user proactive contribution behavior and user responsive contribution behavior; the variable of community image motivation significantly affects both user proactive contribution behavior and user responsive contribution behavior. Practical implications Although it is voluntary, online user voluntary contribution behavior still need to be presented, recognized and affirmed by community. For enterprise-hosted online community managers, they should pay more attention to design the reasonable online community user recognition mechanism with the coexistence of quantity and quality. Originality/value The theoretical contribution in this study is to enrich the existing research theme about enterprise-hosted online product innovation community. First, it conceptualizes two patterns of user recognition mechanisms. Second, it regards the variable of user contribution behavior as the co-existence of proactive contribution and responsive contribution. Third, from the perspective of prosocial behavior theory, it is an important supplement to explain the mechanism of user contribution behavior in enterprise-hosted online product innovation community. Fourth, it deepens the overall understanding of the relationship between user recognition mechanism and user contribution behavior. This study provides theoretical guidance for enterprises how to design reasonable and efficient online product innovation community platform. The theoretical contribution in this study is to enrich the existing research theme about enterprise-hosted online product innovation community. First, it conceptualizes two patterns of user recognition mechanisms. Second, it regards the variable of user contribution behavior as the co-existence of proactive contribution and responsive contribution. Third, from the perspective of prosocial behavior theory, it is an important supplement to explain the mechanism of user contribution behavior in enterprise-hosted online product innovation community. Fourth, it deepens the overall understanding of the relationship between user recognition mechanism and user contribution behavior. This study provides theoretical guidance for enterprises how to design reasonable and efficient online product innovation community platform.