Can’t Stop: How Context and Individual Traits Influence Effectiveness of Different Gradual Interventions for Infinite Scrolling on Short-Form Video Platforms

L.-M. Meinhardt, M. Dragic, M. Colley, K. Lukoff, E. Rukzio

IMWUT 2026

Can’t Stop: How Context and Individual Traits Influence Effectiveness of Different Gradual Interventions for Infinite Scrolling on Short-Form Video PlatformsL.-M. Meinhardt, M. Dragic, M. Colley, K. Lukoff, E. RukzioProceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies 2026Infinite scrolling on short-form video platforms like TikTok encourages prolonged engagement and post-usage regret. Interventions aim to mitigate such behavior, but their effectiveness may depend on the interplay between intervention type, contextual factors, and individual traits. In a 7-day within-subject randomized field study (N=104), we compared a baseline pop-up and two gradually intensifying design frictions (visual and haptic). We evaluated behavioral changes and user experience using objective and subjective measures. Results showed that the pop-up was initially effective but quickly lost impact, whereas the visual gradual intervention sustained subjective ratings the longest. Bayesian modeling revealed that self-regulation traits moderate how participants responded to the three intervention types. For participants with low impulsivity, the type of intervention had little influence on its subjective effectiveness. For participants with high impulsivity, however, differences between intervention types were substantial, with the explicit baseline pop-up being most effective compared to the novel gradual interventions. Contextual factors, in contrast, showed little influence. These findings suggest that intervention modality and individual differences in self-regulation shape intervention effectiveness.https://www.youtube.com/embed/WVAQ7rtmpwE?si=4CYCbne0VhtngOBa

Mind Games! Exploring the Impact of Dark Patterns in Mixed Reality Scenarios

L.-M. Meinhardt, S. Demharter, M. Rietzler, M. Colley, T. Eßmeyer, E. Rukzio

Mobile HCI 2025

Mind Games! Exploring the Impact of Dark Patterns in Mixed Reality ScenariosL.-M. Meinhardt, S. Demharter, M. Rietzler, M. Colley, T. Eßmeyer, E. RukzioProceedings of the ACM on Human-Computer Interaction 2025Mixed Reality (MR) integrates virtual objects with the real world, offering potential but raising concerns about misuse through dark patterns. This study explored the effects of four dark patterns, adapted from prior research, and applied to MR across three targets: places, products, and people. In a two-factorial within-subject study with 74 participants, we analyzed 13 videos simulating MR experiences during a city walk. Results show that all dark patterns significantly reduced user comfort, increased reactance, and decreased the intention to use MR glasses, with the most disruptive effects linked to personal or monetary manipulation. Additionally, the dark patterns of Emotional and Sensory Manipulation and Hiding Information produced similar impacts on the user in MR, suggesting a re-evaluation of current classifications to go beyond deceptive design techniques. Our findings highlight the importance of developing ethical design guidelines and tools to detect and prevent dark patterns as immersive technologies continue to evolve.https://www.youtube.com/embed/tJR6gZsUKg0?si=2pNKp5lK2-v47vsO

Scrolling in the Deep: Analysing Contextual Influences on Intervention Effectiveness during Infinite Scrolling on Social Media

L.-M. Meinhardt, M. Elhaidary, M. Colley, M. Rietzler, JO Rixen, A. Purohit, E. Rukzio

CHI 2025

Scrolling in the Deep: Analysing Contextual Influences on Intervention Effectiveness during Infinite Scrolling on Social MediaL.-M. Meinhardt, M. Elhaidary, M. Colley, M. Rietzler, JO Rixen, A. Purohit, E. RukzioProceedings of the 2025 CHI Conference on Human Factors in Computing Systems Infinite scrolling on social media platforms is designed to encourage prolonged engagement, leading users to spend more time than desired, which can in-turn provoke negative emotions. Interventions to mitigate infinite scrolling have shown initial success, yet users frequently become desensitized due to the lack of contextual relevance. However, understanding how different contextual factors (e.g., current activity, social situation, and emotional state) influence the effectiveness of these interventions is underexplored. We conducted a 7-day user study (N=72) to investigate how these contextual factors affect users' reactance and responsiveness to interventions during infinite scrolling. Our study revealed a complex interplay, with contextual factors such as location, sleepiness, and emotional state playing a significant role in the effectiveness of interventions during infinite scrolling. Overall, our work contributes to a deeper understanding of user effects on interventions and paves the way for developing more tailored and effective interventions during infinite scrolling.https://www.youtube.com/embed/2Vr0DN8fJY4?si=xk8zicK5pfeiwytT

Light My Way: Developing and Exploring a Multimodal Interface to Assist People With Visual Impairments to Exit Highly Automated Vehicles

L.-M. Meinhardt, L. Wilke, M. Elhaidary, J. von Abel, P. Fink, M. Rietzler, M. Colley, E. Rukzio

CHI 2025

Light My Way: Developing and Exploring a Multimodal Interface to Assist People With Visual Impairments to Exit Highly Automated VehiclesL.-M. Meinhardt, L. Wilke, M. Elhaidary, J. von Abel, P. Fink, M. Rietzler, M. Colley, E. RukzioProceedings of the 2025 CHI Conference on Human Factors in Computing SystemsThe introduction of Highly Automated Vehicles has the potential to increase the independence of blind and visually impaired people (BVIPs). However, ensuring safety and situational awareness when exiting these vehicles in unfamiliar environments remains challenging. To address this, we conducted an interactive workshop with N=5 BVIPs to identify their information needs when exiting an HAV and evaluated three prior-developed low-fidelity prototypes. The insights from this workshop guided the development of PathFinder, a multimodal interface combining visual, auditory, and tactile modalities tailored to BVIP's unique needs. In a three-factorial within-between-subject study with N=16 BVIPs, we evaluated PathFinder against an auditory-only baseline in urban and rural scenarios. PathFinder significantly reduced mental demand and maintained high perceived safety in both scenarios, while the auditory baseline led to lower perceived safety in the urban scenario compared to the rural one. Qualitative feedback further supported PathFinder's effectiveness in providing spatial orientation during exiting.https://www.youtube.com/embed/-we2VJLCYgs?si=EWE6NXaDQ6LZ17G6https://www.youtube.com/embed/P7BelipvA-U?si=5Lt8nv_xURBvRCiE

Fly Away: Evaluating the Impact of Motion Fidelity on Optimized User Interface Design via Bayesian Optimization in Automated Urban Air Mobility Simulations

L.-M. Meinhardt, C. Schramm, P. Jansen, M. Colley, E. Rukzio

CHI 2025

Fly Away: Evaluating the Impact of Motion Fidelity on Optimized User Interface Design via Bayesian Optimization in Automated Urban Air Mobility SimulationsL.-M. Meinhardt, C. Schramm, P. Jansen, M. Colley, E. RukzioProceedings of the 2025 CHI Conference on Human Factors in Computing SystemsAutomated Urban Air Mobility (UAM) can improve passenger transportation and reduce congestion, but its success depends on passenger trust. While initial research addresses passengers' information needs, questions remain about how to simulate air taxi flights and how these simulations impact users and interface requirements. We conducted a between-subjects study (N=40), examining the influence of motion fidelity in Virtual-Reality-simulated air taxi flights on user effects and interface design. Our study compared simulations with and without motion cues using a 3-Degrees-of-Freedom motion chair. Optimizing the interface design across six objectives, such as trust and mental demand, we used multi-objective Bayesian optimization to determine the most effective design trade-offs. Our results indicate that motion fidelity decreases users' trust, understanding, and acceptance, highlighting the need to consider motion fidelity in future UAM studies to approach realism. However, minimal evidence was found for differences or equality in the optimized interface designs, suggesting personalized interface designs.https://www.youtube.com/embed/rrhi_h7hfOA?si=eA6D0dlqp-0D8wEzhttps://www.youtube.com/embed/-KCGY-p2WcI?si=uQNdp5gA3e0w6O60

Computer-Implemented Method and Devices for Determining at Least One Astigmatism Parameter of at Least One Eye of a Person

D. Dobbelstein, L. Stoppe, L.-M. Meinhardt, M. Wald, A. Leube

European Patent 2024

Computer-Implemented Method and Devices for Determining at Least One Astigmatism Parameter of at Least One Eye of a PersonD. Dobbelstein, L. Stoppe, L.-M. Meinhardt, M. Wald, A. LeubeEuropean PatentThe present invention relates to a computer-implemented method for determining at least one astigmatism parameter of at least one eye of a person, the method comprising the following steps: a) generating input data configured to comprise at least one position of the at least one eye of the person relative to the measurement device; wherein the at least one position of the at least one eye of the person is determined, in a step iii), by using the measurement device; b) generating outcome data configured to comprise at least one astigmatism parameter of the eye of the person; wherein the at least one astigmatism parameter of the eye of the person is determined, in a step iv), by comparing at least one known feature to at least one reflected feature comprised in the at least one recorded image of the at least one reflected feature in the eye of the person, wherein the position of the at least one eye of the person is considered when the at least one astigmatism parameter of the eye of the person is determined. The present invention further relates to a computer program, a field device, a remote device, a determining device, a data carrier signal, a method for producing a geometrical model of at least one spectacle lens, a method for producing at least one spectacle lens, and a use of an external lens. The present invention provides a fast, easy, versatile, reliable, easy accessible and accurate approach for determining at least one astigmatism parameter of an eye of a person.

Wind Of Change: Investigating Information Visualizations for Passengers and Residents’ Perception of Automated Urban Air Mobility

L.-M. Meinhardt*, M. Colley*, M Tahmid, M. Rädler, E. Rukzio

IMWUT 2024

Wind Of Change: Investigating Information Visualizations for Passengers and Residents’ Perception of Automated Urban Air MobilityL.-M. Meinhardt*, M. Colley*, M Tahmid, M. Rädler, E. RukzioProceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies 2024Automated Urban Air Mobility (UAM) is expected to improve passenger transportation but raises concerns about passenger trust and its impact on residents. We address these issues through three online studies using 360-degree videos. The study on adverse lighting and weather conditions (N=31) shows that bounding box visualizations of other air taxis positively impact passengers' perceived safety. Especially during fog, passengers' perceived safety is reduced when no additional information besides the path is shown. The second study (N=29) extends these findings to emergency scenarios (wind gusts, bird flocks, and rotor breakdown) and shows that visualizations of the alternate path increase perceived safety and trust. Finally, studying the impact of UAM on residents (N=29), we found significant concerns about visual pollution and privacy, especially in the suburbs but also in offices. Our findings provide actionable insights into UAM perception and societal acceptability for future aerial transportation design and infrastructure.https://www.youtube.com/embed/bAVIkfm_M9Q?si=8uHFVf2b9xgwui2R

Hey, What’s Going On? Conveying Traffic Information to People with Visual Impairments in Highly Automated Vehicles: Introducing OnBoard

L.-M. Meinhardt, M. Rück, J. Zähnle, M. Elhaidary, M. Colley, M. Rietzler, E. Rukzio

IMWUT 2024

Hey, What’s Going On? Conveying Traffic Information to People with Visual Impairments in Highly Automated Vehicles: Introducing OnBoardL.-M. Meinhardt, M. Rück, J. Zähnle, M. Elhaidary, M. Colley, M. Rietzler, E. RukzioProceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies 2024Highly Automated Vehicles offer a new level of independence to people who are blind or visually impaired. However, due to their limited vision, gaining knowledge of the surrounding traffic can be challenging. To address this issue, we conducted an interactive, participatory workshop (N=4) to develop an auditory interface and OnBoard - a tactile interface with expandable elements - to convey traffic information to visually impaired people. In a user study with N=14 participants, we explored usability, situation awareness, predictability, and engagement with OnBoard and the auditory interface. Our qualitative and quantitative results show that tactile cues, similar to auditory cues, are able to convey traffic information to users. In particular, there is a trend that participants with reduced visual acuity showed increased engagement with both interfaces. However, the diversity of visual impairments and individual information needs underscores the importance of a highly tailored multimodal approach as the ideal solution.https://www.youtube.com/embed/a4C_Pm8uXzQ?si=BB-hw7JZt7cjOMym

Investigating Infinite Scrolling Behaviour in Social Media Applications and Reasons to Stop

J. O. Rixen, L.-M. Meinhardt, M. Glöckler, M.-L. Ziegenbein, A. Schlothauer, M. Colley, E. Rukzio, J. Gugenheimer

Mobile HCI 2023

Investigating Infinite Scrolling Behaviour in Social Media Applications and Reasons to StopJ. O. Rixen, L.-M. Meinhardt, M. Glöckler, M.-L. Ziegenbein, A. Schlothauer, M. Colley, E. Rukzio, J. GugenheimerProceedings of the ACM on Human-Computer Interaction 2023Today's social media (SM) platforms are toolkits consisting of features with different use cases, some strongly related to habitual and regretful use. Especially Infinite Scrolling (IS) has been reported to make users feel like they are being caught in a loop, regretfully elongating SM sessions. We investigated and defined this loop while unveiling the processes that make users break it. Based on a one-week-long field study (N=46), we unfolded and categorized general reasons for leaving social media and related those to IS. In light of our findings, we argue that SM interventions should not only focus on the app but incorporate the user's context, as most reasons to break SM sessions were not related to the app but the user's general context. Our findings and prior work also indicate the coexistence of multiple loops, which we define as inner (intra-session) loops surrounded by an outer (habitual) loop.

Come Fly With Me: Investigating the Effects of Path Visualizations in Automated Urban Air Mobility

M. Colley*, L.-M. Meinhardt*, A. Fassbender, M. Rietzler, E. Rukzio

IMWUT 2023

Come Fly With Me: Investigating the Effects of Path Visualizations in Automated Urban Air MobilityM. Colley*, L.-M. Meinhardt*, A. Fassbender, M. Rietzler, E. RukzioProceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies 2023Automated Urban Air Mobility will enhance passenger transportation in metropolitan areas in the near future. Potential passengers, however, have little knowledge about this mobility form. Therefore, there could be concerns about safety and low trust. As trajectories are essential information to address these concerns, we evaluated seven path visualizations in an online video-based study (N=99). We found that a path line visualization was rated highest for trust and perceived safety. In a follow-up virtual reality study (N=24), we evaluated the effects of this visualization and of other air traffic flying by. We found that the participants looked at the path line more often when other air traffic was present and that the path line increased trust and predictability of the air taxi's future path.https://www.youtube.com/embed/YuxSIx5ZjTs?si=Ysrf7TjTy87RToPK

EyesOnMe: Investigating Haptic and Visual User Guidance for Near-Eye Positioning of Mobile Phones for Self-Eye-Examinations

L.-M. Meinhardt, K. Van Laerhoven, D. Dobbelstein

EA CHI 2023

EyesOnMe: Investigating Haptic and Visual User Guidance for Near-Eye Positioning of Mobile Phones for Self-Eye-ExaminationsL.-M. Meinhardt, K. Van Laerhoven, D. DobbelsteinExtended Abstracts of the 2023 CHI Conference on Human Factors in Computing SystemsThe scarcity of professional ophthalmic equipment in rural areas and during exceptional situations such as the COVID-19 pandemic highlights the need for tele-ophthalmology. This late-breaking work presents a novel method for guiding users to a specific pose (3D position and 3D orientation) near the eye for mobile self-eye examinations using a smartphone. The user guidance is implemented utilizing haptic and visual modalities to guide the user and subsequently capture a close-up photo of the user’s eyes. In a within-subject user study (n=24), the required time, success rate, and perceived demand for the visual and haptic feedback conditions were examined. The results indicate that haptic feedback was the most efficient and least cognitively demanding in the positioning task near the eye, whereas relying on only visual feedback can be more difficult due to the near focus point or refractive errors.https://www.youtube.com/embed/Rk-np3tPG98?si=IacFTuVZl3YiQz2R

Up, Up and Away – Investigating Information Needs for Helicopter Pilots in Future Urban Air Mobility

L.-M. Meinhardt*, M. Colley*, A. Faßbender, M. Rietzler, E. Rukzio

EA CHI 2023

Up, Up and Away – Investigating Information Needs for Helicopter Pilots in Future Urban Air MobilityL.-M. Meinhardt*, M. Colley*, A. Faßbender, M. Rietzler, E. RukzioExtended Abstracts of the 2023 CHI Conference on Human Factors in Computing SystemsThis qualitative work aims to address the emerging challenges and opportunities through advanced automation and visualization capabilities in the field of helicopter piloting for future Urban Air Mobility. A workshop was conducted with N=6 professional helicopter pilots to gather insights on these topics. The participants discussed key themes, including information needs, user interfaces, and automation. The results unveiled novel opportunities and highlighted challenges for research on aiding helicopter pilots in the fields of obstacle avoidance, map visualization, and air traffic visualization, such as augmenting flight paths to increase their situation awareness.https://www.youtube.com/embed/17dXbcwqU5c?si=ziYIfuhYWzx-hm1r

Get in Touch

Hi, I am

Luca Maxim Meinhardt

About Me

UX Project Lead

Publications

Can’t Stop: How Context and Individual Traits Influence Effectiveness of Different Gradual Interventions for Infinite Scrolling on Short-Form Video Platforms

Mind Games! Exploring the Impact of Dark Patterns in Mixed Reality Scenarios

Scrolling in the Deep: Analysing Contextual Influences on Intervention Effectiveness during Infinite Scrolling on Social Media

Light My Way: Developing and Exploring a Multimodal Interface to Assist People With Visual Impairments to Exit Highly Automated Vehicles

Fly Away: Evaluating the Impact of Motion Fidelity on Optimized User Interface Design via Bayesian Optimization in Automated Urban Air Mobility Simulations

Computer-Implemented Method and Devices for Determining at Least One Astigmatism Parameter of at Least One Eye of a Person

Wind Of Change: Investigating Information Visualizations for Passengers and Residents’ Perception of Automated Urban Air Mobility

Hey, What’s Going On? Conveying Traffic Information to People with Visual Impairments in Highly Automated Vehicles: Introducing OnBoard

Investigating Infinite Scrolling Behaviour in Social Media Applications and Reasons to Stop

Come Fly With Me: Investigating the Effects of Path Visualizations in Automated Urban Air Mobility

EyesOnMe: Investigating Haptic and Visual User Guidance for Near-Eye Positioning of Mobile Phones for Self-Eye-Examinations

Up, Up and Away – Investigating Information Needs for Helicopter Pilots in Future Urban Air Mobility

Projects

Cocktail MOBO

Light Installation

Media Design Degree Program

Halley’s Comet Documentary

Personal Design

Medical Prescription

Violinbau

La Luz

Recent Events

UbiComp 2027

PhD defence

PhD Dissertation submitted

UbiComp 25

Mobile HCI

Heidelberg Laureate Forum

Research Talk at the University of Tokyo

I gave three research talks at CHI’25

300k EUR Funding for Research on Infinite Scrolling

Warming-up at the German PreCHI

Visiting Researcher

Ubicomp 2024

CHI Together

Summer School for Computational Interaction

Ubicomp/ISWC 2023

Automotive UI 2023

Writing Sessions at CHI-Together

Summer School on HCI for Well-being

CHI 2023

German Pre-CHI 2023