VLDB 2026 Research / reviewers in the wild / expert
Dagmar Kern
dblp:51/1343
· DBLP profile ↗
12ranked-venue papers in the field
3as first author
5since 2021 · last 2026
0000-0003-1794-625XORCID · verified
Domains — venue-derived; a paper can count in several
Information Retrieval & Web Search · 11 (3 first)Knowledge Engineering, Semantic Web & Information Systems · 1
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | Cleo: A Transparent and Controllable Chatbot for Conversational CommerceabstractWe demonstrate Cleo, a transparent and controllable conversational product advisor that addresses the challenges of opacity, unpredictability of LLMs, and the complexity of comparisons in conversational commerce. With our chatbot system, we make four contributions: First, we introduce transparency by prompting the LLM to reflect on interpreted user needs, while an auditable ranking mechanism reveals loss values per attribute, explaining ranking decisions. Second, we propose controllability through a hybrid architecture separating deterministic ranking from language generation. A ranker applies categorical filters and numeric loss functions over 3,638 product specifications. Meanwhile, a constrained LLM generates grounded descriptions constrained to catalog evidence, thus mitigating the risk of hallucinated or persuasive content. Third, we provide decision support in the form of natural-language comparisons and a highlights feature. These aim to reduce mental workload by contextualizing specifications relative to user needs. Fourth, we contribute an extensible experimental system for IR and HCI researchers, as well as practitioners of conversational search and recommendation. Unlike traditional faceted search or opaque LLM-only recommenders, our approach allows for fluid conversation while maintaining algorithmic transparency. In a live demonstration, attendees will experience information needs elicitation and reflection, conversational refinement with real-time re-ranking, inspection of per-attribute loss explanations, and AI-generated multi-item comparisons. The system aims to advance the design of transparent and controllable conversational systems that provide support for decision-making during online product search. Kevin Schott, Jan Lattenkamp, Daniel Hienert, Dagmar Kern |
CHIIR | 4 |
| 2026 | "I don't know anything about laptops!" - User Perception of Digital Product Advisors Adapting to Their Knowledge LevelsabstractConversational commerce uses digital assistants to support the search process and decision-making in e-commerce. Effective communication in these interactions can be facilitated by assistants adapting their communication style to users and supporting shared understanding. An open challenge in this context is adapting the presentation of complex product information to users with varying levels of domain knowledge. To investigate strategies for such knowledge-level adaptation, we set up a chatbot-assisted laptop search scenario. In a between-subjects experiment (n = 251), we examined novice and expert perceptions of product attribute recommendations presented as technical information only (T), or augmented with performance categories (TC), attribute explanations (TE), or both (TCE). For novices, approaches with explanations (TE, TCE) were perceived as more helpful and led to higher perceived learning than those without. Novices also rated the combined approach (TCE) more appropriate than the baseline (T) and TC in terms of information quantity, indicating that explanations are crucial to understand and benefit from performance categories. Critically, experts showed no significant differences across conditions, suggesting that providing supplementary information beneficial to novices did not detract from their experience. We distill these findings into four concrete design guidelines for inclusive text-based product advisors in technical domains: use TCE by default; keep a single inclusive interface; avoid standalone categories; and support user agency and personalize to the stated use case. Kevin Schott, Andrea Papenmeier, Daniel Hienert, Dagmar Kern |
CHIIR | 4 |
| 2022 | "Mhm..." - Conversational Strategies For Product Search AssistantsabstractOnline retail has become a popular alternative to in-store shopping. However, unlike in traditional stores, users of online shops need to find the right product on their own without support from expert salespersons. Conversational search could provide a means to compensate for the shortcomings of traditional product search engines. To establish design guidelines for such virtual product search assistants, we studied conversations in a user study (N = 24) where experts supported users in finding the right product for their needs. We annotated the conversations concerning their content and conversational structure and identified recurring conversational strategies. Our findings show that experts actively elicit the users’ information needs using funneling techniques. They also use dialogue-structuring elements and frequently confirm having understood what the client was saying by using discourse markers, e.g., “mhm”. With this work, we contribute insights and design implications for conversational product search assistants. Andrea Papenmeier, Alexander Frummet, Dagmar Kern |
CHIIR | 3 |
| 2021 | Starting Conversations with Search Engines - Interfaces that Elicit Natural Language QueriesabstractSearch systems on the Web rely on user input to generate relevant results. Since early information retrieval systems, users are trained to issue keyword searches and adapt to the language of the system. Recent research has shown that users often withhold detailed information about their initial information need, although they are able to express it in natural language. We therefore conduct a user study (N = 139) to investigate how four different design variants of search interfaces can encourage the user to reveal more information. Our results show that a chatbot-inspired search interface can increase the number of mentioned product attributes by 84% and promote natural language formulations by 139% in comparison to a standard search bar interface. Andrea Papenmeier, Dagmar Kern, Daniel Hienert, Alfred Sliwa, Ahmet Aker, Norbert Fuhr |
CHIIR | 2 |
| 2021 | Dataset of Natural Language Queries for E-CommerceabstractShopping online is more and more frequent in our everyday life. For e-commerce search systems, understanding natural language coming through voice assistants, chatbots or from conversational search is an essential ability to understand what the user really wants. However, evaluation datasets with natural and detailed information needs of product-seekers which could be used for research do not exist. Due to privacy issues and competitive consequences, only few datasets with real user search queries from logs are openly available. In this paper, we present a dataset of 3,540 natural language queries in two domains that describe what users want when searching for a laptop or a jacket of their choice. The dataset contains annotations of vague terms and key facts of 1,754 laptop queries. This dataset opens up a range of research opportunities in the fields of natural language processing and (interactive) information retrieval for product search. Andrea Papenmeier, Dagmar Kern, Daniel Hienert, Alfred Sliwa, Ahmet Aker, Norbert Fuhr |
CHIIR | 2 |
| 2020 | The Role of Word-Eye-Fixations for Query Term PredictionabstractThroughout the search process, the user's gaze on inspected SERPs and websites can reveal his or her search interests. Gaze behavior can be captured with eye tracking and described with word-eye-fixations. Word-eye-fixations contain the user's accumulated gaze fixation duration on each individual word of a web page. In this work, we analyze the role of word-eye-fixations for predicting query terms. We investigate the relationship between a range of in-session features, in particular, gaze data, with the query terms and train models for predicting query terms. We use a dataset of 50 search sessions obtained through a lab study in the social sciences domain. Using established machine learning models, we can predict query terms with comparably high accuracy, even with only little training data. Feature analysis shows that the categories Fixation, Query Relevance and Session Topic contain the most effective features for our task. Masoud Davari, Daniel Hienert, Dagmar Kern, Stefan Dietze |
CHIIR | 3 |
| 2019 | Reading Protocol: Understanding what has been Read in Interactive Information Retrieval TasksabstractIn Interactive Information Retrieval (IIR) experiments the user's gaze motion on web pages is often recorded with eye tracking. The data is used to analyze gaze behavior or to identify Areas of Interest (AOI) the user has looked at. So far, tools for analyzing eye tracking data have certain limitations in supporting the analysis of gaze behavior in IIR experiments. Experiments often consist of a huge number of different visited web pages. In existing analysis tools the data can only be analyzed in videos or images and AOIs for every single web page have to be specified by hand, in a very time consuming process. In this work, we propose the reading protocol software which breaks eye tracking data down to the textual level by considering the HTML structure of the web pages. This has a lot of advantages for the analyst. First and foremost, it can easily be identified on a large scale what has actually been viewed and read on the stimuli pages by the subjects. Second, the web page structure can be used to filter to AOIs. Third, gaze data of multiple users can be presented on the same page, and fourth, fixation times on text can be exported and further processed in other tools. We present the software, its validation, and example use cases with data from three existing IIR experiments. Daniel Hienert, Dagmar Kern, Matthew Mitsui, Chirag Shah 0001, Nicholas J. Belkin |
CHIIR | 2 |
| 2019 | Lessons Learned from Users Reading Highlighted Abstracts in a Digital LibraryabstractFinding relevant documents is essential for researchers of all disciplines. We investigated an approach for supporting searchers in their relevance decision in a digital library by automatically highlighting the most important keywords in abstracts. We conducted an eye-tracking study with 25 subjects and observed very different search and reading behavior which lead to diverse results. Some of the participants liked that highlighted abstracts accelerate their relevance decision, while others found that they disturb the reading flow. What many agree on is that the quality of highlighting is crucial for trust and system credibility. Dagmar Kern, Daniel Hienert, Katrin Angerbauer, Tilman Dingler, Pia Borlund |
CHIIR | 1 |
| 2018 | A LOD Backend Infrastructure for Scientific Search Portals
Benjamin Zapilko, Katarina Boland, Dagmar Kern |
ESWC | 3 |
| 2017 | Evaluating the Usefulness of Visual Features for Supporting Document Triage
Dagmar Kern, Maria Lusky, Dirk Wacker |
TPDL | 1 |
| 2015 | WHOSE - A Tool for Whole-Session Analysis in IIR
Daniel Hienert, Wilko van Hoek, Alina Weber, Dagmar Kern |
ECIR | 4 |
| 2015 | Are There Any Differences in Data Set Retrieval Compared to Well-Known Literature Retrieval?
Dagmar Kern, Brigitte Mathiak |
TPDL | 1 |