VLDB 2026 Research / reviewers in the wild / expert
Chandan Kumar 0003
dblp:86/5830-3
· DBLP profile ↗
15ranked-venue papers
5as first author
5since 2021 · last 2026
0000-0002-2213-6940ORCID · conflict
Domains — the database's venue-derived domains; a paper can count in several
Human-computer interaction and ubiquitous computing · 13 · 4 first-author · 4 since 2021Graphics, computer vision, multimedia, augmented reality and games · 4Artificial intelligence and machine learning · 3 · 2 first-authorApplied, interdisciplinary, general and emerging computing · 2 · 1 first-authorDatabases, data management, data science and information retrieval · 1 · 1 since 2021
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | DUPLet: Dynamic User Modeling for Personalized Cover Letter GenerationabstractComposing tailored cover letters for specific job applications is challenging, particularly when applying for multiple jobs. We present DUPLet, an interactive system that leverages large language models (LLMs) to produce more personalized and authentic cover letters. The key novelty of our system lies in dynamic user modeling that leverages a natural-language description of the user’s profile and preferences, which adapts over time based on provided input and interactions with the system. Based on a resume, job description, and a series of LLM-generated, job-specific questions, DUPLet creates an initial cover letter draft that users can then iteratively refine. We conducted a preliminary evaluation of DUPLet by simulating user interactions with LLMs and using the LLM-as-a-judge paradigm to rate the cover letters on dimensions, such as personalization and authenticity. Results indicate that cover letter variants that involve the user and leverage a dynamically refined natural-language user profile tend to receive higher ratings. Tom Bovie, Bhupender Kumar Saini, Chandan Kumar 0003, Mihai Bâce |
UMAP | 3 |
| 2026 | Virtual User Lab: An Interactive System for Simulating User Perspectives with AI Personas for Ideation and EvaluationabstractDesigners, researchers, and decision-makers often need to reason about diverse user and stakeholder perspectives at early stages, when empirical user research is costly or difficult to repeat. We present the Virtual User Lab (VUL), an interactive system that simulates how different target user groups may respond to product ideas and decision scenarios. VUL allows product teams to define end-user characteristics and personas, configure decision scenarios, and incorporate contextual information to ground responses using language models. This makes it possible to explore how different perspectives react to alternative ideas and to compare them in a structured way, making trade-offs visible. By enabling side-by-side comparison and interaction with these perspectives, the system supports more systematic reasoning about user assumptions. Chandan Kumar 0003, Christian Knecht, Jeremias Lange, Bhupender Kumar Saini, Matthias Peissner |
UMAP | 1 |
| 2025 | What Did My Users Experience? Discovering Visual Stimuli on Graphical User Interfaces of the WebabstractMain tasks of usability experts for Web sites comprise the analysis of user interaction behavior on graphical user interfaces, the discovery of issues, and the derivation of improvements to the interface. The analysis of user interaction behavior and corresponding discovery of issues are made difficult by modern Web interfaces that incorporate dynamic interface elements and that orchestrate complex reactions to user responses. We propose a semi-automated approach for discovering visual stimuli, which capture summarized views of the interface as encountered by users during interaction. Discovered visual stimuli allow for meaningful aggregations of user interactions based on what users encountered on the interface such that the analysis by usability experts can relate the interface views with user interactions correctly and identify arising issues. We provide WebVSD as an implementation of the approach and perform a set of evaluations with real-world Web sites that show the accuracy of proposed methods in isolation and in the tool chain, as well as case studies and a survey of usability experts indicating the usefulness of the suggested approach. Raphael Menges, Steffen Staab, Christoph Schaefer, Tina Walber, Chandan Kumar 0003 |
ACM Trans. Web | 5 |
| 2022 | All Birds Must Fly: The Experience of Multimodal Hands-free Gaming with Gaze and Nonverbal Voice SynchronizationabstractEye tracking has evolved as a promising hands-free interaction mechanism to support people with disabilities. However, its adoption as a control mechanism in the gaming environment is constrained due to erroneous recognition of user intention and commands. Previous studies have suggested combining eye gaze with other modalities like voice input for improved interaction experience. However, speech recognition latency and accuracy is a major bottleneck, and the use of dictated verbal commands can disrupt the flow in gaming environment. Furthermore, several people with physical disabilities also suffer from speech impairments to utter precise verbal voice commands. In this work, we introduce nonverbal voice interaction (NVVI) to synchronize with gaze for an intuitive hands-free gaming experience. We propose gaze and NVVI (e.g., humming) for a spatio-temporal interaction applicable to several modern gaming apps, and developed ‘All Birds Must Fly’ as a representative app. In the experiment, we first compared the gameplay experience of gaze and NVVI (GV) with the conventional mouse and keyboard (MK) in a study with 15 non-disabled participants. The participants could effectively control the game environment with GV (expectedly a bit slower than MK). More importantly, they found GV more engaging, fun, and enjoyable. In a second study with 10 participants, we successfully validated the feasibility of GV with a target user group of people with disabilities. Ramin Hedeshy, Chandan Kumar 0003, Mike Lauer, Steffen Staab |
ICMI | 2 |
| 2021 | Hummer: Text Entry by Gaze and HumabstractText entry by gaze is a useful means of hands-free interaction that is applicable in settings where dictation suffers from poor voice recognition or where spoken words and sentences jeopardize privacy or confidentiality. However, text entry by gaze still shows inferior performance and it quickly exhausts its users. We introduce text entry by gaze and hum as a novel hands-free text entry. We review related literature to converge to word-level text entry by analysis of gaze paths that are temporally constrained by humming. We develop and evaluate two design choices: “HumHum” and “Hummer.” The first method requires short hums to indicate the start and end of a word. The second method interprets one continuous humming as an indication of the start and end of a word. In an experiment with 12 participants, Hummer achieved a commendable text entry rate of 20.45 words per minute, and outperformed HumHum and the gaze-only method EyeSwipe in both quantitative and qualitative measures. Ramin Hedeshy, Chandan Kumar 0003, Raphael Menges, Steffen Staab |
CHI | 2 |
| 2020 | TAGSwipe: Touch Assisted Gaze Swipe for Text EntryabstractThe conventional dwell-based methods for text entry by gaze are typically slow and uncomfortable. A swipe-based method that maps gaze path into words offers an alternative. However, it requires the user to explicitly indicate the beginning and ending of a word, which is typically achieved by tedious gaze-only selection. This paper introduces TAGSwipe, a bi-modal method that combines the simplicity of touch with the speed of gaze for swiping through a word. The result is an efficient and comfortable dwell-free text entry method. In the lab study TAGSwipe achieved an average text entry rate of 15.46 wpm and significantly outperformed conventional swipe-based and dwell-based methods in efficacy and user satisfaction. Chandan Kumar 0003, Ramin Hedeshy, I. Scott MacKenzie, Steffen Staab |
CHI | 1 |
| 2019 | Impact of variable positioning of text prediction in gaze-based text entryabstractText predictions play an important role in improving the performance of gaze-based text entry systems. However, visual search, scanning, and selection of text predictions require a shift in the user's attention from the keyboard layout. Hence the spatial positioning of predictions becomes an imperative aspect of the end-user experience. In this work, we investigate the role of spatial positioning by comparing the performance of three different keyboards entailing variable positions for text predictions. The experiment result shows no significant differences in the text entry performance, i.e., displaying suggestions closer to visual fovea did not enhance the text entry rate of participants, however they used more keystrokes and backspace. This implies to the inessential usage of suggestions when it is in the constant visual attention of users, resulting in increased cost of correction. Furthermore, we argue that the fast saccadic eye movements undermines the spatial distance optimization in prediction positioning. Korok Sengupta, Raphael Menges, Chandan Kumar 0003, Steffen Staab |
ETRA | 3 |
| 2019 | TouchGazePath: Multimodal Interaction with Touch and Gaze Path for Secure Yet Efficient PIN EntryabstractWe present TouchGazePath, a multimodal method for entering personal identification numbers (PINs). Using a touch-sensitive display showing a virtual keypad, the user initiates input with a touch at any location, glances with their eye gaze on the keys bearing the PIN numbers, then terminates input by lifting their finger. TouchGazePath is not susceptible to security attacks, such as shoulder surfing, thermal attacks, or smudge attacks. In a user study with 18 participants, TouchGazePath was compared with the traditional Touch-Only method and the multimodal Touch+Gaze method, the latter using eye gaze for targeting and touch for selection. The average time to enter a PIN with TouchGazePath was 3.3 s. This was not as fast as Touch-Only (as expected), but was about twice as fast the Touch+Gaze. TouchGazePath was also more accurate than Touch+Gaze. TouchGazePath had high user ratings as a secure PIN input method and was the preferred PIN input method for 11 of 18 participants. Chandan Kumar 0003, Daniyal Akbari, Raphael Menges, I. Scott MacKenzie, Steffen Staab |
ICMI | 1 |
| 2019 | Improving User Experience of Eye Tracking-Based Interaction: Introspecting and Adapting InterfacesabstractEye tracking systems have greatly improved in recent years, being a viable and affordable option as digital communication channel, especially for people lacking fine motor skills. Using eye tracking as an input method is challenging due to accuracy and ambiguity issues, and therefore research in eye gaze interaction is mainly focused on better pointing and typing methods. However, these methods eventually need to be assimilated to enable users to control application interfaces. A common approach to employ eye tracking for controlling application interfaces is to emulate mouse and keyboard functionality. We argue that the emulation approach incurs unnecessary interaction and visual overhead for users, aggravating the entire experience of gaze-based computer access. We discuss how the knowledge about the interface semantics can help reducing the interaction and visual overhead to improve the user experience. Thus, we propose the efficient introspection of interfaces to retrieve the interface semantics and adapt the interaction with eye gaze. We have developed a Web browser, GazeTheWeb, that introspects Web page interfaces and adapts both the browser interface and the interaction elements on Web pages for gaze input. In a summative lab study with 20 participants, GazeTheWeb allowed the participants to accomplish information search and browsing tasks significantly faster than an emulation approach. Additional feasibility tests of GazeTheWeb in lab and home environment showcase its effectiveness in accomplishing daily Web browsing activities and adapting large variety of modern Web pages to suffice the interaction for people with motor impairment. Raphael Menges, Chandan Kumar 0003, Steffen Staab |
ACM Trans. Comput. Hum. Interact. | 2 |
| 2018 | Enhanced representation of web pages for usability analysis with eye trackingabstractEye tracking as a tool to quantify user attention plays a major role in research and application design. For Web page usability, it has become a prominent measure to assess which sections of a Web page are read, glanced or skipped. Such assessments primarily depend on the mapping of gaze data to a Web page representation. However, current representation methods, a virtual screenshot of the Web page or a video recording of the complete interaction session, suffer either from accuracy or scalability issues. We present a method that identifies fixed elements on Web pages and combines user viewport screenshots in relation to fixed elements for an enhanced representation of the page. We conducted an experiment with 10 participants and the results signify that analysis with our method is more efficient than a video recording, which is an essential criterion for large scale Web studies. Raphael Menges, Hanadi Tamimi, Chandan Kumar 0003, Tina Walber, Christoph Schaefer, Steffen Staab |
ETRA | 3 |
| 2018 | Enhanced representation of web pages for usability analysis with eye trackingabstractEye tracking as a tool to quantify user attention plays a major role in research and application design. For Web page usability, it has become a prominent measure to assess which sections of a Web page are read, glanced or skipped. Such assessments primarily depend on the mapping of gaze data to a Web page representation. However, current representation methods, a virtual screenshot of the Web page or a video recording of the complete interaction session, suffer either from accuracy or scalability issues. We present a method that identifies fixed elements on Web pages and combines user viewport screenshots in relation to fixed elements for an enhanced representation of the page. We conducted an experiment with 10 participants and the results signify that analysis with our method is more efficient than a video recording, which is an essential criterion for large scale Web studies. Raphael Menges, Hanadi Tamimi, Chandan Kumar 0003, Tina Walber, Christoph Schaefer, Steffen Staab |
ETRA | 3 |
| 2018 | Hands-free web browsing: enriching the user experience with gaze and voice modalityabstractHands-free browsers provide an effective tool for Web interaction and accessibility, overcoming the need for conventional input sources. Current approaches to hands-free interaction are primarily categorized in either voice or gaze-based modality. In this work, we investigate how these two modalities could be integrated to provide a better hands-free experience for end-users. We demonstrate a multimodal browsing approach combining eye gaze and voice inputs for optimized interaction, and to suffice user preferences with unimodal benefits. The initial assessment with five participants indicates improved performance for the multimodal prototype in comparison to single modalities for hands-free Web browsing. Korok Sengupta, Min Ke, Raphael Menges, Chandan Kumar 0003, Steffen Staab |
ETRA | 4 |
| 2017 | Assessing the Usability of Gaze-Adapted Interface against Conventional Eye-Based Input EmulationabstractIn recent years, eye tracking systems have greatly improved, beginning to play a promising role as an input medium. Eye trackers can be used for application control either by simply emulating the mouse and keyboard devices in the traditional graphical user interface, or by customized interfaces for eye gaze events. In this work, we evaluate these two approaches to assess their impact in usability. We present a gaze-adapted Twitter application interface with direct interaction of eye gaze input, and compare it to Twitter in a conventional browser interface with gaze-based mouse and keyboard emulation. We conducted an experimental study, which indicates a significantly better subjective user experience for the gaze-adapted approach. Based on the results, we argue the need of user interfaces interacting directly to eye gaze input to provide an improved user experience, more specifically in the field of accessibility. Chandan Kumar 0003, Raphael Menges, Steffen Staab |
CBMS | 1 |
| 2017 | Analyzing the Impact of Cognitive Load in Evaluating Gaze-Based TypingabstractGaze-based virtual keyboards provide an effective interface for text entry by eye movements. The efficiency and usability of these keyboards have traditionally been evaluated with conventional text entry performance measures such as words per minute, keystrokes per character, backspace usage, etc. However, in comparison to the traditional text entry approaches, gaze-based typing involves natural eye movements that are highly correlated with human brain cognition. Employing eye gaze as an input could lead to excessive mental demand, and in this work we argue the need to include cognitive load as an eye typing evaluation measure. We evaluate three variations of gaze-based virtual keyboards, which implement variable designs in terms of word suggestion positioning. The conventional text entry metrics indicate no significant difference in the performance of the different keyboard designs. However, STFT (Short-time Fourier Transform) based analysis of EEG signals indicate variances in the mental workload of participants while interacting with these designs. Moreover, the EEG analysis provides insights into the users cognition variation for different typing phases and intervals, which should be considered in order to improve eye typing usability. Korok Sengupta, Jun Sun 0011, Raphael Menges, Chandan Kumar 0003, Steffen Staab |
CBMS | 4 |
| 2009 | Estimating Risk of Picking a Sentence for Document Summarization
Chandan Kumar 0003, Prasad Pingali, Vasudeva Varma |
CICLing | 1 |