Gender Differences in Participation and Reward on Stack Overflow

Programming is a valuable skill in the labor market, making the underrepresentation of women in computing an increasingly important issue. Online question and answer platforms serve a dual purpose in this field: they form a body of knowledge useful as a reference and learning tool, and they provide opportunities for individuals to demonstrate credible, verifiable expertise. Issues, such as male-oriented site design or overrepresentation of men among the site's elite may therefore compound the issue of women's underrepresentation in IT. In this paper we audit the differences in behavior and outcomes between men and women on Stack Overflow, the most popular of these Q&A sites. We observe significant differences in how men and women participate in the platform and how successful they are. For example, the average woman has roughly half of the reputation points, the primary measure of success on the site, of the average man. Using an Oaxaca-Blinder decomposition, an econometric technique commonly applied to analyze differences in wages between groups, we find that most of the gap in success between men and women can be explained by differences in their activity on the site and differences in how these activities are rewarded. Specifically, 1) men give more answers than women and 2) are rewarded more for their answers on average, even when controlling for possible confounders such as tenure or buy-in to the site. Women ask more questions and gain more reward per question. We conclude with a hypothetical redesign of the site's scoring system based on these behavioral differences, cutting the reputation gap in half

Interferometric SAR DEMs for Forest Change in Uganda 2000–2012

Monitoring changes in forest height, biomass and carbon stock is important for understanding the drivers of forest change, clarifying the geography and magnitude of the fluxes of the global carbon budget and for providing input data to REDD+. The objective of this study was to investigate the feasibility of covering these monitoring needs using InSAR DEM changes over time and associated estimates of forest biomass change and corresponding net CO2 emissions. A wall-to-wall map of net forest change for Uganda with its tropical forests was derived from two Digital Elevation Model (DEM) datasets, namely the SRTM acquired in 2000 and TanDEM-X acquired around 2012 based on Interferometric SAR (InSAR) and based on the height of the phase center. Errors in the form of bias, as well as parallel lines and belts having a certain height shift in the SRTM DEM were removed, and the penetration difference between X- and C-band SAR into the forest canopy was corrected. On average, we estimated X-band InSAR height to decrease by 7 cm during the period 2000–2012, corresponding to an estimated annual CO2 emission of 5 Mt for the entirety of Uganda. The uncertainty of this estimate given as a 95% confidence interval was 2.9–7.1 Mt. The presented method has a number of issues that require further research, including the particular SRTM biases and artifact errors; the penetration difference between the X- and C-band; the final height adjustment; and the validity of a linear conversion from InSAR height change to AGB change. However, the results corresponded well to other datasets on forest change and AGB stocks, concerning both their geographical variation and their aggregated values.publishedVersio

How guilty and innocent suspects perceive the police and themselves: suspect interviews in Germany

Purpose: Suspects are central participants of a police interview and can provide crucial information on the interview interactions with the interviewers. This study examined how the way suspects perceive interviews relates to (a) their reported status of being guilty or innocent and (b) their decision to confess or deny. Methods: A total of 250 convicted offenders completed a two-part questionnaire on their perceptions during the most recent suspect interview in which they had confessed to or denied a crime they had committed (Part 1) or not committed (Part 2). Results: Participants reported a total of 334 police interviews – 223 for which they reported being guilty and 111 for which they reported being innocent. An exploratory factor analysis showed that three latent factors described how they viewed the interviewers and themselves: Respectful-Open Behaviors (non-accusatorial interviewer behaviour, and no pressure in suspects), Confession-Oriented Tactics by the interviewer (minimization and maximization tactics), and Suspects’ Psychological Distress (insecurity, fear, and lack of self-confidence). Suspects perceived less Psychological Distress and less Respectful-Open Behaviors in reported innocent (vs. guilty) interview situations. In reported guilty interview situations, confessions were associated positively with Respectful-Open Behaviors and Suspects’ Psychological Distress, whereas denials were associated positively with Confession-Oriented Tactics. Innocent interview situations showed a positive correlation between confessions and Suspects’ Psychological Distress. Conclusions: In this study, suspects deliver an important message to the police and the legal system: The findings substantiate the benefits of an open-minded interviewing approach, and fail to support a confession-oriented interrogation approach

Prediction of speech intelligibility based on a correlation metric in the envelope power spectrum domain

A powerful tool to investigate speech perception is the use of speech intelligibility prediction models. Recently, a model was presented, termed correlation-based speechbased envelope power spectrum model (sEPSMcorr) [1], based on the auditory processing of the multi-resolution speech-based Envelope Power Spectrum Model (mr-sEPSM) [2], combined with the correlation back-end of the Short-Time Objective Intelligibility measure (STOI) [3]. The sEPSMcorr can accurately predict NH data for a broad range of listening conditions, e.g., additive noise, phase jitter and ideal binary mask processing

Effects of slow- and fast-acting compression on hearing impaired listeners’ consonant-vowel identification in interrupted noise

There is conflicting evidence about the relative benefit of slow- and fast-acting compression for speech intelligibility. It has been hypothesized that fast-acting compression improves audibility at low signal-to-noise ratios (SNRs) but may distort the speech envelope at higher SNRs. The present study investigated the effects of compression with a nearly instantaneous attack time but either fast (10 ms) or slow (500 ms) release times on consonant identification in hearing-impaired listeners. Consonant–vowel speech tokens were presented at a range of presentation levels in two conditions: in the presence of interrupted noise and in quiet (with the compressor “shadow-controlled” by the corresponding mixture of speech and noise). These conditions were chosen to disentangle the effects of consonant audibility and noise-induced forward masking on speech intelligibility. A small but systematic intelligibility benefit of fast-acting compression was found in both the quiet and the noisy conditions for the lower speech levels. No detrimental effects of fast-acting compression were observed when the speech level exceeded the level of the noise. These findings suggest that fast-acting compression provides an audibility benefit in fluctuating interferers when compared with slow-acting compression while not substantially affecting the perception of consonants at higher SNRs

Exploring possible links between Quaternary aggradation in the Upper Rhine Graben and the glaciation history of northern Switzerland

The Quaternary filling of the Upper Rhine Graben is an excellent archive to reconstruct sediment dynamics in response to climate change, in particular related to past glaciations of the Swiss Alpine Foreland. Here, a sediment sequence recovered by drilling for exploration purposes near Kronau is investigated, using a combination of sedimentological logging, provenance studies (heavy minerals and clast petrography), and luminescence dating. Several phases of coarse sediment aggradation are identified that possibly correlate to Marine Isotope Stages (MIS) 12 (478-424 ka), 10 (374-337 ka), 8 (300-243 ka), 6 (191-130 ka) and/or 4 (71-57 ka), and 2 (29-14 ka). Several of these phases have previously also been reported from cores recovered in the major Quaternary depo-centre near Heidelberg. This suggests that the observed coarse aggradation in the Upper Rhine Graben can be assigned to various glaciations in northern Switzerland: Mohlin (MIS 12), Habsburg (MIS 10 or 8), Beringen (MIS 6), an unnamed glacial advance during MIS 4, and Birrfeld (MIS 2). However, due to the limited data available, this hypothesis and the suggested correlations require further confirmation by applying the approach presented here to further cores from the Upper Rhine Graben.</p

Random Sampling with Removal

Abstract Random sampling is a classical tool in constrained optimization. Under favorable conditions, the optimal solution subject to a small subset of randomly chosen constraints violates only a small subset of the remaining constraints. Here we study the following variant that we call random sampling with removal: suppose that after sampling the subset, we remove a fixed number of constraints from the sample, according to an arbitrary rule. Is it still true that the optimal solution of the reduced sample violates only a small subset of the constraints? The question naturally comes up in situations where the solution subject to the sampled constraints is used as an approximate solution to the original problem. We study random sampling with removal in a generalized, completely abstract setting where we assign to each subset R of the constraints an arbitrary set V (R) of constraints disjoint from R; in applications, V (R) corresponds to the constraints violated by the optimal solution subject to only the constraints in R. Furthermore, our results are parametrized by the dimension δ, i.e., we assume that every set R has a subset B of size at most δ with the same set of violated constraints. This is the first time this generalized setting is studied. In this setting, we prove matching upper and lower bounds for the expected number of constraints violated by a random sample, after the removal of k elements. For a large range of values of k, the new upper bounds improve the previously best bounds for LPtype problems, which moreover had only been known in special cases. We show that this bound on special LP-type problems can be derived in the much more general setting of violator spaces, and with very elementary proofs