VLDB 2026 Research / reviewers in the wild / expert
Barbara Keller
dblp:136/2568
· DBLP profile ↗
16ranked-venue papers
0as first author
7since 2021 · last 2026
—ORCID · conflict
Domains — the database's venue-derived domains; a paper can count in several
Applied, interdisciplinary, general and emerging computing · 5 · 3 since 2021Human-computer interaction and ubiquitous computing · 4 · 4 since 2021Databases, data management, data science and information retrieval · 3 · 3 since 2021Theory of computation · 3 · 1 since 2021Artificial intelligence and machine learning · 2Systems, architecture and hardware · 1 · 1 since 2021
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | Race to the Big Lab: Gender Disparities in Large Team Collaboration and Its Impact on Early Academic CareersabstractThis study investigates the role of large-team collaboration in shaping early-career scholars’ career development, with a focus on gender disparities. Using publication and collaboration data from SciSciNet in Computer Science, we capture the social capital accumulation process in academia with a neighborhood-based centrality metric and publication counts. Synthetic difference-in-differences (SDID) is applied to estimate the impact of early experience in large-team collaboration on subsequent research careers. Results indicate that junior scholars participating in large-team research significantly improve their network centrality, indicating more frequent collaborations with influential scholars, and produce approximately 0.75 more publications per year. Meanwhile, we document persistent gender gaps: men are 16% more likely to access large-team collaborations. These findings highlight large-team collaboration as both a source of career acceleration and a mechanism of gender inequality. We conclude with implications for equity promotion and strategies enabling more inclusive collaboration. Anh Duong Nguyen, Barbara Keller |
CHI | 3 |
| 2026 | Distributed Quantum Advantage in Locally Checkable Labeling Problems
Alkida Balliu, Filippo Casagrande, Francesco d'Amore 0001, Massimo Equi, Barbara Keller, Henrik Lievonen, Dennis Olivetti, Gustav Schmid, Jukka Suomela |
SODA | 5 |
| 2025 | Integrated or Segregated? User Behavior Change After Cross-Party Interactions on RedditabstractIt has been a widely shared concern that social media reinforces echo chambers of like-minded users and exacerbate political polarization. While fostering interactions across party lines is recognized as an important strategy to break echo chambers, there is a lack of empirical evidence on whether users will actually become more integrated or instead more segregated following such interactions on real social media platforms. We fill this gap by inspecting how users change their community engagement after receiving a cross-party reply in the U.S. politics discussion on Reddit. More specifically, we investigate if they increase their activity in communities of the opposing party, or in communities of their own party. We find that receiving a cross-party reply to a comment in a non-partisan discussion space is not significantly associated with increased out-party subreddit activity, unless the comment itself is already a reply to another comment. Meanwhile, receiving a cross-party reply is significantly associated with increased in-party subreddit activity, but the effect is comparable to that of receiving a same-party reply. Our results reveal a highly conditional depolarization effect following cross-party interactions in spurring out-party community engagement, which is likely part of a more general dynamic of feedback-boosted activity. Corrado Monti, Barbara Keller, Mikko Kivelä |
ICWSM | 3 |
| 2025 | Mind the Gap: Gender, Homophily and the Glass Ceiling in Academic NetworksabstractThis study examines the gender distribution within collaboration and mentorship networks across several scientific disciplines, namely Physics, Material Science, Computer Science, Chemistry, Biology and Psychology in the last two decades. Our analysis reveals that the proportions of women in these fields range from 24% to 49%. Despite these variations, all disciplines show evidence of gender-based homophily in their networks, and there are indications for the presence of a glass ceiling effect. Specifically, we observed that women are under-represented in high-status positions with respect to their number of mentees in mentorship networks and their scientific contributions within collaboration networks. These findings highlight longstanding gender disparities in scientific collaboration and mentoring practices, along with cumulative impacts on measured performances of researchers across disciplines. Using a network approach, this study not only extends the methodological work on quantifying gender gaps but also provides actionable insights for the design of more inclusive systems with gender-equitable access to mentorship and collaboration opportunities. Anh Duong Nguyen, Jiaming Jiang, Barbara Keller |
Proc. ACM Hum. Comput. Interact. | 3 |
| 2023 | Minority Stress Experienced by LGBTQ Online Communities during the COVID-19 PandemicabstractThe COVID-19 pandemic has disproportionately impacted the lives of minorities, such as members of the LGBTQ community (lesbian, gay, bisexual, transgender, and queer) due to pre-existing social disadvantages and health disparities. Although extensive research has been carried out on the impact of the COVID-19 pandemic on different aspects of the general population's lives, few studies are focused on the LGBTQ population. In this paper, we develop and evaluate two sets of machine learning classifiers using a pre-pandemic and a during-pandemic dataset to identify Twitter posts exhibiting minority stress, which is a unique pressure faced by the members of the LGBTQ population due to their sexual and gender identities. We demonstrate that our best pre- and during-pandemic models show strong and stable performance for detecting posts that contain minority stress. We investigate the linguistic differences in minority stress posts across pre- and during-pandemic periods. We find that anger words are strongly associated with minority stress during the COVID-19 pandemic. We explore the impact of the pandemic on the emotional states of the LGBTQ population by adopting propensity score-based matching to perform a causal analysis. The results show that the LGBTQ population have a greater increase in the usage of cognitive words and worsened observable attribute in the usage of positive emotion words than the group of the general population with similar pre-pandemic behavioral attributes. Our findings have implications for the public health domain and policy-makers to provide adequate support, especially with respect to mental health, to the LGBTQ population during future crises. Yunhao Yuan 0002, Barbara Keller, Talayeh Aledavood |
ICWSM | 3 |
| 2023 | Mental Health Coping Stories on Social Media: A Causal-Inference Study of Papageno EffectabstractThe Papageno effect concerns how media can play a positive role in preventing and mitigating suicidal ideation and behaviors. With the increasing ubiquity and widespread use of social media, individuals often express and share lived experiences and struggles with mental health. However, there is a gap in our understanding about the existence and effectiveness of the Papageno effect in social media, which we study in this paper. In particular, we adopt a causal-inference framework to examine the impact of exposure to mental health coping stories on individuals on Twitter. We obtain a Twitter dataset with ∼ 2M posts by ∼ 10K individuals. We consider engaging with coping stories as the Treatment intervention, and adopt a stratified propensity score approach to find matched cohorts of Treatment and Control individuals. We measure the psychosocial shifts in affective, behavioral, and cognitive outcomes in longitudinal Twitter data before and after engaging with the coping stories. Our findings reveal that, engaging with coping stories leads to decreased stress and depression, and improved expressive writing, diversity, and interactivity. Our work discusses the practical and platform design implications in supporting mental wellbeing. Yunhao Yuan 0002, Koustuv Saha, Barbara Keller, Erkki Tapio Isometsä, Talayeh Aledavood |
WWW | 3 |
| 2021 | Efficient Load-Balancing through Distributed Token DroppingabstractWe introduce a new graph problem, the token dropping game, and we show how to solve it efficiently in a distributed setting. We use the token dropping game as a tool to design an efficient distributed algorithm for stable orientations and more generally for locally optimal semi-matchings. The prior work by Czygrinow et al. (DISC 2012) finds a stable orientation in O(Δ^5) rounds in graphs of maximum degree Δ, while we improve it to O(Δ^4) and also prove a lower bound of Ω(Δ). For the more general problem of locally optimal semi-matchings, the prior upper bound is O(S^5) and our new algorithm runs in O(C · S^4) rounds, which is an improvement for C = o(S); here C and S are the maximum degrees of customers and servers, respectively. Sebastian Brandt 0002, Barbara Keller, Joel Rybicki, Jukka Suomela, Jara Uitto |
SPAA | 2 |
| 2020 | Brief Announcement: Efficient Load-Balancing Through Distributed Token Dropping
Sebastian Brandt 0002, Barbara Keller, Joel Rybicki, Jukka Suomela, Jara Uitto |
DISC | 2 |
| 2019 | Insights into Advanced Dynamic Pricing Systems at Hotel Booking Platforms
Michael Möhring, Barbara Keller, Rainer Schmidt 0001 |
ENTER | 2 |
| 2018 | Revenue Management Information Systems for Small and Medium-Sized Hotels: Empirical Insights into the Current Situation in Germany
Michael Möhring, Barbara Keller, Rainer Schmidt 0001, Alfred Zimmermann |
KES-IDT | 2 |
| 2017 | Digital Enterprise Architecture Management in Tourism - State of the Art and Future Directions
Rainer Schmidt 0001, Michael Möhring, Barbara Keller, Alfred Zimmermann, Martina Toni, Laura Di Pietro |
KES-IDT (2) | 3 |
| 2016 | A lower bound for the distributed Lovász local lemmaabstractWe show that any randomised Monte Carlo distributed algorithm for the Lovász local lemma requires Omega(log log n) communication rounds, assuming that it finds a correct assignment with high probability. Our result holds even in the special case of d = O(1), where d is the maximum degree of the dependency graph. By prior work, there are distributed algorithms for the Lovász local lemma with a running time of O(log n) rounds in bounded-degree graphs, and the best lower bound before our work was Omega(log* n) rounds [Chung et al. 2014]. Sebastian Brandt 0002, Orr Fischer, Juho Hirvonen, Barbara Keller, Tuomo Lempiäinen, Joel Rybicki, Jukka Suomela, Jara Uitto |
STOC | 4 |
| 2015 | Homophily and the Glass Ceiling Effect in Social NetworksabstractThe glass ceiling effect has been defined in a recent US Federal Commission report as "the unseen, yet unbreakable barrier that keeps minorities and women from rising to the upper rungs of the corporate ladder, regardless of their qualifications or achievements". It is well documented that many societies and organizations exhibit a glass ceiling. In this paper we formally define and study the glass ceiling effect in social networks and propose a natural mathematical model, called the biased preferential attachment model, that partially explains the causes of the glass ceiling effect. This model consists of a network composed of two types of vertices, representing two sub-populations, and accommodates three well known social phenomena: (i) the "rich get richer" mechanism, (ii) a minority-majority partition, and (iii) homophily. We prove that our model exhibits a strong moment glass ceiling effect and that all three conditions are necessary, i.e., removing any one of them will prevent the appearance of a glass ceiling effect. Additionally, we present empirical evidence taken from a mentor-student network of researchers (derived from the DBLP database) that exhibits both a glass ceiling effect and the above three phenomena. Chen Avin, Barbara Keller, Zvi Lotker, Claire Mathieu, David Peleg, Yvonne-Anne Pignolet |
ITCS | 2 |
| 2015 | Overcoming Obstacles with AntsabstractConsider a group of mobile finite automata, referred to as agents, located in the origin of an infinite grid. The grid is occupied by obstacles, i.e., sets of cells that can not be entered by the agents. In every step, an agent can sense the states of the co-located agents and is allowed to move to any neighboring cell of the grid not blocked by an obstacle. We assume that the circumference of each obstacle is finite but allow the number of obstacles to be unbounded. The task of the agents is to cooperatively find a treasure, hidden in the grid by an adversary. In this work, we show how the agents can utilize their simple means of communication and their constant memory to systematically explore the grid and to locate the treasure in finite time. As integral part of the agents' behavior, we present a method that allows a group of six agents to follow a straight line, even if the line is partially obstructed by obstacles, and to discover all free cells along this line. In total, our search protocol requires nine agents. Tobias Langner 0001, Barbara Keller, Jara Uitto, Roger Wattenhofer |
OPODIS | 2 |
| 2013 | Convergence in (Social) Influence Networks
Silvio Frischknecht, Barbara Keller, Roger Wattenhofer |
DISC | 2 |
| 2006 | Combining signals from spotted cDNA microarrays obtained at different scanning intensitiesabstractMOTIVATION: The analysis of spotted cDNA microarrays involves scanning of color signals from fluorescent dyes. A common problem is that a given scanning intensity is not usually optimal for all spotted cDNAs. Specifically, some spots may be at the saturation limit, resulting in poor separation of signals from different tissues or conditions. The problem may be addressed by multiple scans with varying scanning intensities. Multiple scanning intensities raise the question of how to combine different signals from the same spot, particularly when measurement error is not negligible. RESULTS: This paper suggests a non-linear latent regression model for this purpose. It corrects for biases caused by the saturation limit and efficiently combines data from multiple scans. Combining multiple scans also allows reduction of technical error particularly for cDNA spots with low signal. The procedure is exemplified using cDNA expression data from maize. AVAILABILITY: All methods were implemented using standard procedures available in the SAS/STAT module of the SAS System. Programming statements are available from the first author upon request. CONTACT: [email protected] SUPPLEMENTARY INFORMATION: The supplementary data are available at Bioinformatics online. Hans-Peter Piepho, Barbara Keller, Nadine Hoecker, Frank Hochholdinger |
Bioinform. | 2 |