The Social World of Content Abusers in Community Question Answering

Community-based question answering platforms can be rich sources of information on a variety of specialized topics, from finance to cooking. The usefulness of such platforms depends heavily on user contributions (questions and answers), but also on respecting the community rules. As a crowd-sourced service, such platforms rely on their users for monitoring and flagging content that violates community rules. Common wisdom is to eliminate the users who receive many flags. Our analysis of a year of traces from a mature Q&A site shows that the number of flags does not tell the full story: on one hand, users with many flags may still contribute positively to the community. On the other hand, users who never get flagged are found to violate community rules and get their accounts suspended. This analysis, however, also shows that abusive users are betrayed by their network properties: we find strong evidence of homophilous behavior and use this finding to detect abusive users who go under the community radar. Based on our empirical observations, we build a classifier that is able to detect abusive users with an accuracy as high as 83%.Comment: Published in the proceedings of the 24th International World Wide Web Conference (WWW 2015

HadISD: a quality-controlled global synoptic report database for selected variables at long-term stations from 1973--2011

[Abridged] This paper describes the creation of HadISD: an automatically quality-controlled synoptic resolution dataset of temperature, dewpoint temperature, sea-level pressure, wind speed, wind direction and cloud cover from global weather stations for 1973--2011. The full dataset consists of over 6000 stations, with 3427 long-term stations deemed to have sufficient sampling and quality for climate applications requiring sub-daily resolution. As with other surface datasets, coverage is heavily skewed towards Northern Hemisphere mid-latitudes. The dataset is constructed from a large pre-existing ASCII flatfile data bank that represents over a decade of substantial effort at data retrieval, reformatting and provision. These raw data have had varying levels of quality control applied to them by individual data providers. The work proceeded in several steps: merging stations with multiple reporting identifiers; reformatting to netCDF; quality control; and then filtering to form a final dataset. Particular attention has been paid to maintaining true extreme values where possible within an automated, objective process. Detailed validation has been performed on a subset of global stations and also on UK data using known extreme events to help finalise the QC tests. Further validation was performed on a selection of extreme events world-wide (Hurricane Katrina in 2005, the cold snap in Alaska in 1989 and heat waves in SE Australia in 2009). Although the filtering has removed the poorest station records, no attempt has been made to homogenise the data thus far. Hence non-climatic, time-varying errors may still exist in many of the individual station records and care is needed in inferring long-term trends from these data. A version-control system has been constructed for this dataset to allow for the clear documentation of any updates and corrections in the future.Comment: Published in Climate of the Past, www.clim-past.net/8/1649/2012/. 31 pages, 23 figures, 9 pages. For data see http://www.metoffice.gov.uk/hadobs/hadis

Targeting Non-Cognitive Skills to Improve Cognitive Outcomes: Evidence from a Remedial Education Intervention

A growing body of research highlights the importance of non-cognitive skills as determinants of young people's cognitive outcomes at school. However, little evidence exists about the effects of policies that specifically target students' non-cognitive skills as a way to improve educational achievements. In this paper, we shed light on this issue by studying a remedial education programme aimed at English secondary school pupils at risk of school exclusion and with worsening educational trajectories. The main peculiarity of this intervention is that it solely targets students' non-cognitive skills – such as self-confidence, locus of control, self-esteem and motivation – with the aim of improving pupils' records of attendance and end-of-compulsory-education (age 16) cognitive outcomes. We evaluate the effect of the policy on test scores in standardized national exams at age-16 using both least squares and propensity-score matching methods. Additionally, we exploit repeated observations on pupils’ test scores to control for unobservables that might affect students’ outcomes and selection into the programme. We find little evidence that the programme significantly helped treated youths to improve their age-16 test outcomes. We also find little evidence of heterogeneous policy effects along a variety of dimensions.cognitive and non-cognitive skills; policy evaluation; secondary schooling

The impact of young motherhood on education, employment and marriage

The poor socio-economic outcomes of women who have their first child when young are well documented. However, the policy implications of this association depend upon the causal mechanisms that underlie it. Recent studies in the US and UK have used miscarriage as an instrument to identify the direct causal impact of young childbearing – with US research suggesting that early child-bearing may even have a beneficial impact upon mother’s outcomes. This paper uses this method to examine this issue for a new Australian panel of young women. No evidence is found for an adverse impact of young childbirth on education, labour market, income or location. Instead these outcomes follow the patterns that might be expected on the basis of selection effects. On the other hand, young motherhood does have an impact on partnering outcomes. Being a young mother reduces the likelihood of being legally married (instead of defacto partnered) when aged in the late 20s. Also, having a child in the early rather than late 20s leads to a greater likelihood of being a lone parent at around age 30.teenage mothers; miscarriage

Anyone Can Become a Troll: Causes of Trolling Behavior in Online Discussions

In online communities, antisocial behavior such as trolling disrupts constructive discussion. While prior work suggests that trolling behavior is confined to a vocal and antisocial minority, we demonstrate that ordinary people can engage in such behavior as well. We propose two primary trigger mechanisms: the individual's mood, and the surrounding context of a discussion (e.g., exposure to prior trolling behavior). Through an experiment simulating an online discussion, we find that both negative mood and seeing troll posts by others significantly increases the probability of a user trolling, and together double this probability. To support and extend these results, we study how these same mechanisms play out in the wild via a data-driven, longitudinal analysis of a large online news discussion community. This analysis reveals temporal mood effects, and explores long range patterns of repeated exposure to trolling. A predictive model of trolling behavior shows that mood and discussion context together can explain trolling behavior better than an individual's history of trolling. These results combine to suggest that ordinary people can, under the right circumstances, behave like trolls.Comment: Best Paper Award at CSCW 201

Holland Hospital: Improving Pneumonia Care by Hardwiring Process Enhancements

Outlines successful strategies for improving care for pneumonia, including implementing core measure teams, concurrent reviews, financial incentives, a focus on system factors, preprinted order sets, and reassigning tasks. Presents lessons learned

Conservation Value and Permeability of Neotropical Oil Palm Landscapes for Orchid Bees

The proliferation of oil palm plantations has led to dramatic changes in tropical landscapes across the globe. However, relatively little is known about the effects of oil palm expansion on biodiversity, especially in key ecosystem-service providing organisms like pollinators. Rapid land use change is exacerbated by limited knowledge of the mechanisms causing biodiversity decline in the tropics, particularly those involving landscape features. We examined these mechanisms by undertaking a survey of orchid bees, a well-known group of Neotropical pollinators, across forest and oil palm plantations in Costa Rica. We used chemical baits to survey the community in four regions: continuous forest sites, oil palm sites immediately adjacent to forest, oil palm sites 2km from forest, and oil palm sites greater than 5km from forest. We found that although orchid bees are present in all environments, orchid bee communities diverged across the gradient, and community richness, abundance, and similarity to forest declined as distance from forest increased. In addition, mean phylogenetic distance of the orchid bee community declined and was more clustered in oil palm. Community traits also differed with individuals in oil palm having shorter average tongue length and larger average geographic range size than those in the forest. Our results indicate two key features about Neotropical landscapes that contain oil palm: 1) oil palm is selectively permeable to orchid bees and 2) orchid bee communities in oil palm have distinct phylogenetic and trait structure compared to communities in forest. These results suggest that conservation and management efforts in oil palm-cultivating regions should focus on landscape features.This work was supported by a Hosteling International-Austin Travel Fellowship (http://www.hiusa.org/austin) and a grant from the Graduate Program in Ecology, Evolution and Behavior at the University of Texas (http://www.biosci.utexas.edu/graduate/ee​b/default.aspx) to GL. GL was supported by a US National Science Foundation Graduate Research Fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Integrative BiologyEmail: [email protected]