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

Applying machine learning techniques to identify companies at higher risk of ESG controversy

ESG controversies may have enormous consequences for an individual company, its customers, investors, and other stakeholders. The objective of this work is to identify companies at high risk of ESG controversy based on public ESG data. By using machine learning solutions, early indicators in ESG data can be identified that provide insight into how likely a company is to face an ESG controversy. By using Random Forest models, the proportion of companies with a controversy among the flagged companies can be increased by 93, 5.6and 4.3times for the Environmental, Social and Governance pillar, respectively

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

Equal Access to Post-Secondary Education: The Sisyphean Impact of Flagging Test Scores of Persons with Disabilities

In view of the social stigma associated with disabilities, and the inherent costs of providing accommodations to disabled students, the opportunity for bias within the admissions selection process is clear. As a result, the practice of flagging standardized tests has come under increasing scrutiny. The practice of distinguishing test takers having a disability from those who do not runs counter to the social policy of inclusion, and prevents disabled individuals from enjoying the benefits of equal citizenship. Part II of this paper provides a brief overview of the prejudice disabled individuals have endured throughout history, and discusses some early movements toward change. Part III discusses the legality of flagging test scores and provides an overview of federal laws and professional standards applicable to the practice. Part IV discusses the practice of flagging and the use of accommodations in standardized testing, and evaluates the empirical evidence obtained from standard and nonstandard test administrations in the context of flagging. The section concludes with a brief discussion of why some testing entities stopped flagging test scores. Part V discusses the continued practice of flagging test scores received on the Law School Admission Test (LSAT) and the Medical College Admission Test (MCAT) and examines the empirical evidence used to justify the practice. The section concludes with an analysis of the leading case addressing flagging scores received on professional exams. Part VI provides commentary on the propriety of flagging tests and provides recommendations for change to eliminate the stigmatizing effects of segregating students with disabilities in the admissions process

Composite Scores for Transplant Center Evaluation: A New Individualized Empirical Null Method

Risk-adjusted quality measures are used to evaluate healthcare providers while controlling for factors beyond their control. Existing healthcare provider profiling approaches typically assume that the risk adjustment is perfect and the between-provider variation in quality measures is entirely due to the quality of care. However, in practice, even with very good models for risk adjustment, some between-provider variation will be due to incomplete risk adjustment, which should be recognized in assessing and monitoring providers. Otherwise, conventional methods disproportionately identify larger providers as outliers, even though their provider effects need not be "extreme.'' Motivated by efforts to evaluate the quality of care provided by transplant centers, we develop a composite evaluation score based on a novel individualized empirical null method, which robustly accounts for overdispersion due to unobserved risk factors, models the marginal variance of standardized scores as a function of the effective center size, and only requires the use of publicly-available center-level statistics. The evaluations of United States kidney transplant centers based on the proposed composite score are substantially different from those based on conventional methods. Simulations show that the proposed empirical null approach more accurately classifies centers in terms of quality of care, compared to existing methods

Equal Access to Post-Secondary Education: The Sisyphean Impact of Flagging Test Scores of Persons with Disabilities

In view of the social stigma associated with disabilities, and the inherent costs of providing accommodations to disabled students, the opportunity for bias within the admissions selection process is clear. As a result, the practice of flagging standardized tests has come under increasing scrutiny. The practice of distinguishing test takers having a disability from those who do not runs counter to the social policy of inclusion, and prevents disabled individuals from enjoying the benefits of equal citizenship. Part II of this paper provides a brief overview of the prejudice disabled individuals have endured throughout history, and discusses some early movements toward change. Part III discusses the legality of flagging test scores and provides an overview of federal laws and professional standards applicable to the practice. Part IV discusses the practice of flagging and the use of accommodations in standardized testing, and evaluates the empirical evidence obtained from standard and nonstandard test administrations in the context of flagging. The section concludes with a brief discussion of why some testing entities stopped flagging test scores. Part V discusses the continued practice of flagging test scores received on the Law School Admission Test (LSAT) and the Medical College Admission Test (MCAT) and examines the empirical evidence used to justify the practice. The section concludes with an analysis of the leading case addressing flagging scores received on professional exams. Part VI provides commentary on the propriety of flagging tests and provides recommendations for change to eliminate the stigmatizing effects of segregating students with disabilities in the admissions process