Süleyman Özdel

dblp:247/8585 · DBLP profile ↗
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11ranked-venue papers
6as first author
10since 2021 · last 2026
0000-0002-3390-6154ORCID · corroborated

Domains — the database's venue-derived domains; a paper can count in several

Human-computer interaction and ubiquitous computing · 8 · 5 first-author · 8 since 2021Graphics, computer vision, multimedia, augmented reality and games · 5 · 3 first-author · 5 since 2021Applied, interdisciplinary, general and emerging computing · 3 · 1 first-author · 2 since 2021Software engineering, systems software and programming languages · 1
YearPublicationVenuePosition
2026 VIVA Stimuli: A Web-Based Platform for Eye Tracking Stimuli
abstract
Reproducibility in eye-tracking research is increasingly important as researchers conduct diverse experiments and seek to validate or replicate findings. However, exact replication remains challenging due to differences in laboratory practices and experimental setups. Inconsistent stimulus presentation can yield divergent metrics from identical oculomotor behavior, yet the stimulus layer remains largely unstandardized. Existing tools often require programming expertise or depend on specific hardware vendors. We introduce VIVA Stimuli, a web-based platform for standardized eye-tracking stimulus presentation. It provides configurable task types, including fixation, smooth pursuit, cognitive load, blink, slippage, content display, and questionnaires within a unified environment. The platform supports any eye-tracking technology, including wearable and screen-based VOG trackers, LFI sensors, and EOG devices. ArUco markers enable synchronization for trackers with scene cameras, while a WebSocket architecture ensures temporal synchronization for those without. A visual experiment flow editor allows protocols to be exported and shared, enabling identical stimulus replication across laboratories.
Süleyman Özdel, Virmarie Maquiling, Kadir Burak Buldu, Yasmeen Abdrabou, Enkelejda Kasneci
ETRA1
2026 Understanding Password Preferences, Memorability, and Security through a Human-Centered Lens
abstract
Passwords remain the primary authentication method, yet user-created passwords are often the weakest due to the security–usability trade-off. Although AI-based password generators are emerging, little is known about their effectiveness and user perceptions. This eye-tracking study examined how behavior during password creation, selection, and memorization relates to objective and subjective password quality. Four password models, three AI-based (DeepSeek-API, ChatGPT-API, PassGPT) and one rule-based random generator, generated suggestions from participants’ self-generated passwords across four website contexts. Eye movements were recorded throughout the experiment. Results confirm the expected trade-off between AI-generated password strength and human memorability but also reveal a novel behavioral link. Despite stronger AI-generated passwords, participants favored self-generated ones. Notably, visual attention to contextual cues was significantly correlated with higher password entropy. This suggests that security is shaped not only by the generation tool but also by users’ visual engagement with contextual cues, highlighting the potential of attention-driven security design.
Duru Paker, Süleyman Özdel, Enkelejda Kasneci
ETRA2
2026 Secure Storage and Privacy-Preserving Scanpath Comparison via Garbled Circuits in Eye Tracking ETRA008
abstract
With the growing use of eye tracking on VR and mobile platforms, gaze data is increasing. While scanpath comparison is important to gaze behavior analysis, existing methods lack privacy-preserving capabilities for real-world use. We present a garbled-circuit (GC)-based approach enabling secure storage and privacy-preserving scanpath comparison under the semi-honest model. It supports two configurations: (1) a two-party setting where the data owner and processor jointly compute similarity scores without revealing their inputs, and (2) a server-assisted setting where encrypted scanpaths are stored and processed while the data owner remains offline. All decryption and comparison operations are executed inside the GC. Experiments on three eye-tracking datasets evaluate fidelity, runtime, and communication, and show secure results for MultiMatch, ScanMatch, and SubsMatch closely match plaintext outcomes, with manageable runtime and communication overhead. Tests under various network conditions indicate that the design remains feasible for real-world privacy-preserving scanpath analysis and can be extended to other GC-based behavioral algorithms.
Süleyman Özdel, Amr Nader, Yasmeen Abdrabou, Enkelejda Kasneci
Proc. ACM Hum. Comput. Interact.1
2025 From Passive Watching to Active Learning: Empowering Proactive Participation in Digital Classrooms with AI Video Assistant
Anna Bodonhelyi, Enkeleda Thaqi, Süleyman Özdel, Efe Bozkir, Enkelejda Kasneci
CHI3
2025 Examining the Role of LLM-Driven Interactions on Attention and Cognitive Engagement in Virtual Classrooms
Süleyman Özdel, Can Sarpkaya, Efe Bozkir, Hong Gao 0008, Enkelejda Kasneci
EDM1
2025 From Gaze to Data: Privacy and Societal Challenges of Using Eye-tracking Data to Inform GenAI Models
Yasmeen Abdrabou, Süleyman Özdel, Virmarie Maquiling, Efe Bozkir, Enkelejda Kasneci
ETRA2
2025 Eye-Tracked Virtual Reality: A Comprehensive Survey on Methods and Privacy Challenges
abstract
The latest developments in computer hardware, sensor technologies, and artificial intelligence can make virtual reality (VR) and virtual spaces an important part of human everyday life. Eye tracking offers not only a hands-free way of interaction but also the possibility of a deeper understanding of human visual attention and cognitive processes in VR. Despite these possibilities, eye-tracking data also reveal users’ privacy-sensitive attributes when combined with the information about the presented stimulus. To address all, this survey first covers major works in eye tracking, VR, and privacy areas between 2012 and 2022. While eye tracking in VR part covers the computational eye-tracking pipeline from pupil detection and gaze estimation to offline data analysis, for privacy and security, we focus on eye-based authentication as well as computational methods to preserve the privacy of individuals and their eye-tracking data in VR. Later, we outline three main directions by focusing on privacy. In summary, this survey presents an extensive literature review of the utmost possibilities of eye tracking in VR and their privacy implications.
Efe Bozkir, Süleyman Özdel, Mengdi Wang 0002, Brendan David-John, Hong Gao 0008, Kevin R. B. Butler, Eakta Jain, Enkelejda Kasneci
Proc. IEEE2
2024 A Transformer-Based Model for the Prediction of Human Gaze Behavior on Videos
abstract
Eye-tracking applications that utilize the human gaze in video understanding tasks have become increasingly important. To effectively automate the process of video analysis based on eye-tracking data, it is important to accurately replicate human gaze behavior. However, this task presents significant challenges due to the inherent complexity and ambiguity of human gaze patterns. In this work, we introduce a novel method for simulating human gaze behavior. Our approach uses a transformer-based reinforcement learning algorithm to train an agent that acts as a human observer, with the primary role of watching videos and simulating human gaze behavior. We employed an eye-tracking dataset gathered from videos generated by the VirtualHome simulator, with a primary focus on activity recognition. Our experimental results demonstrate the effectiveness of our gaze prediction method by highlighting its capability to replicate human gaze behavior and its applicability for downstream tasks where real human-gaze is used as input.
Süleyman Özdel, Yao Rong 0001, Mert Albaba, Yen-Ling Kuo, Xi Wang 0021, Enkelejda Kasneci
ETRA1
2024 Gaze-Guided Graph Neural Network for Action Anticipation Conditioned on Intention
abstract
Humans utilize their gaze to concentrate on essential information while perceiving and interpreting intentions in videos. Incorporating human gaze into computational algorithms can significantly enhance model performance in video understanding tasks. In this work, we address a challenging and innovative task in video understanding: predicting the actions of an agent in a video based on a partial video. We introduce the Gaze-guided Action Anticipation algorithm, which establishes a visual-semantic graph from the video input. Our method utilizes a Graph Neural Network to recognize the agent’s intention and predict the action sequence to fulfill this intention. To assess the efficiency of our approach, we collect a dataset containing household activities generated in the VirtualHome environment, accompanied by human gaze data of viewing videos. Our method outperforms state-of-the-art techniques, achieving a 7% improvement in accuracy for 18-class intention recognition. This highlights the efficiency of our method in learning important features from human gaze data.
Süleyman Özdel, Yao Rong 0001, Mert Albaba, Yen-Ling Kuo, Xi Wang 0021, Enkelejda Kasneci
ETRA1
2024 Privacy-preserving Scanpath Comparison for Pervasive Eye Tracking
abstract
As eye tracking becomes pervasive with screen-based devices and head-mounted displays, privacy concerns regarding eye-tracking data have escalated. While state-of-the-art approaches for privacy-preserving eye tracking mostly involve differential privacy and empirical data manipulations, previous research has not focused on methods for scanpaths. We introduce a novel privacy-preserving scanpath comparison protocol designed for the widely used Needleman-Wunsch algorithm, a generalized version of the edit distance algorithm. Particularly, by incorporating the Paillier homomorphic encryption scheme, our protocol ensures that no private information is revealed. Furthermore, we introduce a random processing strategy and a multi-layered masking method to obfuscate the values while preserving the original order of encrypted editing operation costs. This minimizes communication overhead, requiring a single communication round for each iteration of the Needleman-Wunsch process. We demonstrate the efficiency and applicability of our protocol on three publicly available datasets with comprehensive computational performance analyses and make our source code publicly accessible.
Süleyman Özdel, Efe Bozkir, Enkelejda Kasneci
Proc. ACM Hum. Comput. Interact.1
2019 A New Network Anomaly Detection Method Based on Header Information Using Greedy Algorithm
abstract
Network anomaly detection is an important and rapidly growing area. In this paper, we propose a new network anomaly detection method based on the probability distributions of header information. The distances between the distributions of packet headers are calculated to reflect the main characteristics of the network. These are calculated using the Greedy algorithm which eliminates some requirements associated with Kullback-Leibler divergence such as having the same rank of the probability distributions. Then, Support Vector Machine classifier is used in the detection phase to reduce false alarm rates and to make the system adaptive for different networks. This algorithm is tested on the real data collected from Boğaziçi University network and MIT Darpa 2000 dataset.
Çagatay Ates, Süleyman Özdel, Emin Anarim
CoDIT2