Tests alternative to higher criticism for high-dimensional means under sparsity and column-wise dependence

We consider two alternative tests to the Higher Criticism test of Donoho and Jin [Ann. Statist. 32 (2004) 962-994] for high-dimensional means under the sparsity of the nonzero means for sub-Gaussian distributed data with unknown column-wise dependence. The two alternative test statistics are constructed by first thresholding $L_1$ and $L_2$ statistics based on the sample means, respectively, followed by maximizing over a range of thresholding levels to make the tests adaptive to the unknown signal strength and sparsity. The two alternative tests can attain the same detection boundary of the Higher Criticism test in [Ann. Statist. 32 (2004) 962-994] which was established for uncorrelated Gaussian data. It is demonstrated that the maximal $L_2$-thresholding test is at least as powerful as the maximal $L_1$-thresholding test, and both the maximal $L_2$ and $L_1$-thresholding tests are at least as powerful as the Higher Criticism test.Comment: Published in at http://dx.doi.org/10.1214/13-AOS1168 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Early-age Digital Experience Helps Form IT Identity and Its Impact on Workplace Performance

One of the most anticipated questions in the digital age is how the generation who grew up with digital technologies will behave in the workplace. We investigate the role of early-age digital experience on performance drawing on IT identity theory. Specifically, we hypothesized that early-age digital experience indirectly relates to job performance and work innovation sequentially via IT identity and digital creativity. Additionally, perceived managerial support amplifies IT identity’s influences on digital creativity as well as the indirect effects of early-age digital experience on work results. Data collected via a multiple-source and multiple-wave survey from 281 employees in a large Internet company support the research model. This research enriches the understanding of what drives individuals’ digital creativity and demonstrates that employees with early-age digital experience are critical resources for organizational competitive advantage in a digital economy. Practical implications for employees’ early-age digital use and workplace management are discussed

A new multiple testing method in the dependent case

The most popular multiple testing procedures are stepwise procedures based on $P$-values for individual test statistics. Included among these are the false discovery rate (FDR) controlling procedures of Benjamini--Hochberg [J. Roy. Statist. Soc. Ser. B 57 (1995) 289--300] and their offsprings. Even for models that entail dependent data, $P$-values based on marginal distributions are used. Unlike such methods, the new method takes dependency into account at all stages. Furthermore, the $P$-value procedures often lack an intuitive convexity property, which is needed for admissibility. Still further, the new methodology is computationally feasible. If the number of tests is large and the proportion of true alternatives is less than say 25 percent, simulations demonstrate a clear preference for the new methodology. Applications are detailed for models such as testing treatments against control (or any intraclass correlation model), testing for change points and testing means when correlation is successive.Comment: Published in at http://dx.doi.org/10.1214/08-AOS616 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Does Collaboration Always Enhance Work Efficiency? Investigating Collective IS Use from a Process Perspective

Previous studies have focused mainly on individual IS use, while empirical evidence on collective IS use remains limited. Collective IS use involves interdependent instances of individual IS use within a common work process to fulfill collaborative work. This paper investigates the impact of collective IS use on collaboration performance, what form of collective IS use is efficient, and how to improve work efficiency. Drawing on coordination theory and taking a process perspective, we conceptualize two forms of collective IS use: asynchronous use and synchronous use. Objective data from a high-tech company reveals that asynchronous use improves work efficiency in terms of the time to complete a workflow, while synchronous use prolongs the time resulting in lower work efficiency. We further investigate the moderating role of worker repetitiveness, manager involvement, and task routineness. This study contributes to understanding collective IS use and offers guidance for optimizing collaboration process design

Boundary conditions of the emotional exhaustion-unsafe behavior link: the dark side of group norms and personal control

The article of record as published may be found at http://dx.doi.org/10.1007/sI0490-015-9455-7This study focuses on the conditions under which emotional exhaustion leads to employee unsafe behavior. In a sample of 592 construction workers nested in 33 groups, we found that both emotional exhaustion and unsafe behavior norms were positively related to unsafe behavior by employees. Unsafe behavior norms moderated the relationship between emotional exhaustion and unsafe behavior, such that high group unsafe behavior norms strengthened the emotional exhaustion-employee unsafe behavior link. Furthermore, results indicated a three-way interaction effect in which employees with high emotional exhaustion conducted the highest levels of unsafe behavior when both group unsafe behavior norms and personal control over work were high. This paper provides important implications on understanding the influence of group norms on employee unsafe behavior, as well as its magnifying effect with personal control on the emotional exhaustion-unsafe behavior link.National Natural Science Foundation of ChinaFulbright ScholarshipCenter for Statistical Science, Peking UniversityKey Laboratory of Mathematical Economics and Quantitative Finance (Peking University, Ministry of EducationGrant no. 10901010Grant No. 7150217

How do leaders react when treated unfairly? Leader narcissism and self-interested behavior in response to unfair treatment

In this article we employ a trait activation framework to examine how unfairness perceptions influence narcissistic leaders’ self-interested behavior, and the downstream implications of these effects for employees’ pro-social and voice behaviors. Specifically, we propose that narcissistic leaders are particularly likely to engage in self-interested behavior when they perceive that their organizations treat them unfairly, and that this self-interested behavior in turn decreases followers’ pro-social behavior and voice. Data from a multisource, time-lagged survey of 211 team leaders and 1,205 subordinates provided support for the hypothesized model. Implications for theory and practice are discussed

Are narcissists more creative? Only if we believe it: How narcissism can relate to creativity

The relationship between narcissism and creativity has inspired interesting debates for decades. Drawing on a new perspective, the current study tried to explain how narcissism influences others’ creativity evaluation in the organizational context. Based on the theory of impression management, we suggested that narcissism and creativity may have a more complex relationship rather than a simple linear link. To test this relationship, we conducted a survey of 596 subordinates and 60 leaders in three high-technology companies. The result showed that there was an inverted U-shaped relationship between narcissism and creativity evaluation. Moreover, personal reputation mediated this curvilinear relationship and this relationship was significant only when narcissists were low in political skill. Theoretical and practical implications, limitations and future directions have also been discussed

Chromatin dysregulation and DNA methylation at transcription start sites associated with transcriptional repression in cancers.

Although promoter-associated CpG islands have been established as targets of DNA methylation changes in cancer, previous studies suggest that epigenetic dysregulation outside the promoter region may be more closely associated with transcriptional changes. Here we examine DNA methylation, chromatin marks, and transcriptional alterations to define the relationship between transcriptional modulation and spatial changes in chromatin structure. Using human papillomavirus-related oropharyngeal carcinoma as a model, we show aberrant enrichment of repressive H3K9me3 at the transcriptional start site (TSS) with methylation-associated, tumor-specific gene silencing. Further analysis identifies a hypermethylated subtype which shows a functional convergence on MYC targets and association with CREBBP/EP300 mutation. The tumor-specific shift to transcriptional repression associated with DNA methylation at TSSs was confirmed in multiple tumor types. Our data may show a common underlying epigenetic dysregulation in cancer associated with broad enrichment of repressive chromatin marks and aberrant DNA hypermethylation at TSSs in combination with MYC network activation