Geometric influences

We present a new definition of influences in product spaces of continuous distributions. Our definition is geometric, and for monotone sets it is identical with the measure of the boundary with respect to uniform enlargement. We prove analogs of the Kahn-Kalai-Linial (KKL) and Talagrand's influence sum bounds for the new definition. We further prove an analog of a result of Friedgut showing that sets with small "influence sum" are essentially determined by a small number of coordinates. In particular, we establish the following tight analog of the KKL bound: for any set in $\mathbb{R}^n$ of Gaussian measure $t$, there exists a coordinate $i$ such that the $i$th geometric influence of the set is at least $ct(1-t)\sqrt{\log n}/n$, where $c$ is a universal constant. This result is then used to obtain an isoperimetric inequality for the Gaussian measure on $\mathbb{R}^n$ and the class of sets invariant under transitive permutation group of the coordinates.Comment: Published in at http://dx.doi.org/10.1214/11-AOP643 the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org

Exploring Causal Influences

Recent data mining techniques exploit patterns of statistical independence in multivariate data to make conjectures about cause/effect relationships. These relationships can be used to construct causal graphs, which are sometimes represented by weighted node-link diagrams, with nodes representing variables and combinations of weighted links and/or nodes showing the strength of causal relationships. We present an interactive visualization for causal graphs (ICGs), inspired in part by the Influence Explorer. The key principles of this visualization are as follows: Variables are represented with vertical bars attached to nodes in a graph. Direct manipulation of variables is achieved by sliding a variable value up and down, which reveals causality by producing instantaneous change in causally and/or probabilistically linked variables. This direct manipulation technique gives users the impression they are causally influencing the variables linked to the one they are manipulating. In this context, we demonstrate the subtle distinction between seeing and setting of variable values, and in an extended example, show how this visualization can help a user understand the relationships in a large variable set, and with some intuitions about the domain and a few basic concepts, quickly detect bugs in causal models constructed from these data mining techniques

Gandhi’s Many Influences and Collaborators

In Gandhi's Printing Press, Isabel Hofmeyr introduces readers to the nuances of the newspaper in a far-flung colony in the age when mail and news traveled by ship and when readers were encouraged by Gandhi to read slowly and deeply. This article explores the ways in which Thoreau's concept of slow reading influenced Gandhi and Hofmeyr herself. She discusses the community that surrounded Gandhi and the role it played in supporting the newspaper. Yet, I argue, the role of women of all races as well as Coloured and black South African men in leading, modeling, and shaping the movement of resistance to pass laws and other racist legislation might have been integrated more into the main narrative. Gandhi's newspaper, Indian Opinion, reported on the pass law protests of the African women of Bloemfontein, and Abdurahman's APO newspaper (popular in the Coloured community) reported on Gandhi's protests. Indian Opinion included speeches given by John Dube, and it often praised Dube and the work at Ohlange and reprinted stories from the black press. I offer these remarks to supplement Hofmeyr's fascinating account by providing additional information in portraying the newspaper in its historical and social context

Cultural Influences in Probabilistic Thinking

Concerns about students' difficulties in statistics and probability and a lack of research in this area outside of western countries led to a case study which explored form five (14 to 16 year olds) students' ideas in this area. The study focussed on probability, descriptive statistics and graphical representations. This paper presents and discusses the ways in which students made sense of probability constructs (equally likely and proportional reasoning) obtained from the individual interviews. The findings were interpreted in relation to cultural perspective. The findings revealed that many of the students used strategies based on cultural experiences (beliefs, everyday and school experiences) and intuitive strategies. While the results of the study confirm a number of findings of other researchers, the findings go beyond those discussed in the literature. The use of beliefs, everyday and school experiences was considerably more common than that discussed in literature. The paper concludes by suggesting some implications for teachers and researchers

Familial influences on the full range of variability in attention and activity levels during adolescence: A longitudinal twin study

AbstractTo investigate familial influences on the full range of variability in attention and activity across adolescence, we collected maternal ratings of 339 twin pairs at ages 12, 14, and 16, and estimated the transmitted and new familial influences on attention and activity as measured by the Strengths and Weaknesses of Attention-Deficit/Hyperactivity Disorder Symptoms and Normal Behavior Scale. Familial influences were substantial for both traits across adolescence: genetic influences accounted for 54%–73% (attention) and 31%–73% (activity) of the total variance, and shared environmental influences accounted for 0%–22% of the attention variance and 13%–57% of the activity variance. The longitudinal stability of individual differences in attention and activity was largely accounted for by familial influences transmitted from previous ages. Innovations over adolescence were also partially attributable to familial influences. Studying the full range of variability in attention and activity may facilitate our understanding of attention-deficit/hyperactivity disorder's etiology and intervention.</jats:p

Dispositional Influences on Attributions Concerning Absenteeism

Because the degree to which absenteeism is within or beyond an employee\u27s control is a significant yet unresolved issue in the absence literature, it is important to understand the factors which influence employees\u27 attributions about the causes of absence events. As a result of recent research suggesting that personality variables are important influences on work attitudes and behaviors, the present study took a dispositional approach in investigating the predictors of employee absence attributions. Using data collected from three sources, between-subjects analyses suggested a number of dispositional influences on absence attributions. Within-subjects analyses suggested that the factors leading to external attributions vary widely across individuals