Author: artun.sepken

As interactive systems become more complex, designers need ways to describe and compare interactions beyond individual features or interfaces. One approach that appears repeatedly in HCI research is the use of taxonomies: structured ways of classifying interactions, systems and design choices. Rather than founding direct solutions, taxonomies help clarify what kind of interaction is taking place and under which conditions.

In the context of interruptions and flow, taxonomies are useful because interruptions are not all the same. A notification on a phone, a system alert in a cockpit or a haptic warning in a wearable device may all interrupt attention, but they do so through different interaction channels and with different consequences.

Early taxonomies of human–system interaction

Agah and Tanie propose one of the early comprehensive taxonomies for research on human interactions with intelligent systems. Their framework classifies interaction research along several dimensions: application domain, research approach, system autonomy, interaction distance and interaction media.¹

What is important here is not the specific categories themselves, but the idea that interaction can be analyzed across multiple layers at the same time. For example, an interaction can be local or remote, involve visual or auditory feedback also operate with varying degrees of system autonomy. This already suggests that interruptions should not be treated as a single design problem, but as events shaped by media or system behavior.

Agah later expands this work into a broader research taxonomy that includes human-computer, human-machine and human-robot interactions.²

The taxonomy emphasizes that intelligent systems increasingly share space and tasks with humans, rather than operating in isolation. From an interaction design perspective, this is a key shift: interruptions now happen inside shared environments not just between a user and a screen.

Interaction media and attention

One part of Agah’s taxonomy that is especially relevant to interruption design is interactionmedia. Interaction can happen through visual displays, audio signals, tactile feedback, body movements, voice or combinations of these. Each medium places different demands on attention.²

For example, visual interruptions often require users to shift gaze and visual focus, while auditory interruptions can break concentration even when the user is not looking at a device. Tactile feedback may be less intrusive in some contexts but can still disrupt fine motor tasks. Taxonomies help make these differences explicit instead of treating all notifications as equivalent.

This becomes important when thinking about flow. Flow relies on sustained attention and smooth interaction. An interruption that forces a modality switch (for example, from visual focus to auditory alert) may break flow more strongly than one that stays within the same modality.

From system-centered to human-centered taxonomies

While early taxonomies often focused on systems, devices or tasks, Augstein and Neumayr argue for a human-centered taxonomy of interaction modalities. Their framework classifies interaction based on what humans can actively sense and produce, rather than on specific technologies or devices.³

This shift matters for interaction design because technologies change quickly, but human perceptual capabilities change slowly. By grounding classification in human senses and actions, the taxonomy remains useful even as devices evolve. For interruption design, this suggests that the critical question is not “what device delivers the interruption,” but “how the interruption is perceived by the human.”

Augstein and Neumayr also highlight that many existing taxonomies reduce interaction to a narrow set of modalities; typically vision, audition and touch.³

In practice, however, interactions often combine modalities or rely on subtle perceptual hints. Ignoring this complexity can lead to blunt design decisions, such as defaulting to visual notifications in contexts where visual attention is already overloaded.

Taxonomies as design tools, not checklists

Across these papers, taxonomies are not presented as rigid classification systems but as thinking tools. They help designers and researchers ask better questions: What kind of interaction is this? Through which sensory system does it operate? How autonomous is the system? How close is it to the user?

In the context of interruptions, this means moving away from treating notifications as a single UX pattern. Instead, interruptions can be understood as events that vary along multiple dimensions, each with different effects on attention, flow and recovery.

This perspective supports a more nuanced approach to interaction design. Rather than optimizing interruption frequency or timing in isolation, we as designers can reason about how different interaction modalities and system characteristics shape the interruption experience as a whole.

Positioning within the research trajectory

Within this research project, taxonomies provide a structural bridge between research findings on interruptions and later design strategies for recovery and flow. They offer a shared language for describing interaction complexity without reducing it to simple metrics.

By combining early system-oriented taxonomies with more recent human-centered approaches, interaction design can better account for how interruptions are perceived, processed and integrated into everyday interaction.

References (APA 7)

1. Agah, A., & Tanie, K. (1999). Taxonomy of research on human interactions with intelligent systems. IEEE.
2. Agah, A. (2000). Human interactions with intelligent systems: Research taxonomy. Computers & Electrical Engineering, 27(1), 71–107.
3. Augstein, M., & Neumayr, T. (2019). A human-centered taxonomy of interaction modalities and devices. Interacting with Computers, 31(5), 451–476. https://doi.org/10.1093/iwc/iwz003

AI Assistance Disclaimer:
AI tools were used at certain stages of the research process, primarily for source exploration, grammar refinement and structural editing. All conceptual development, analysis and final writing were made by the author.

Notifications are one of the most visible and disruptive interaction patterns in contemporary digital systems. They are designed to provide timely information, yet they frequently interrupt ongoing tasks, fragment attention and impose cognitive and emotional costs on users. For interaction design and UX, notifications are not a secondary feature but a main mechanism through which systems attract user attention.

This blog focuses on research that examines how notifications affect productivity, attention and emotional state and also what these findings imply for UX design.

Fragmented work as the default condition

Research by Mark, Gonzalez and Harris shows that modern knowledge work is inherently fragmented. Through observational studies of information workers, they demonstrate that work is characterized by frequent task switching, interruptions and activities rather than long periods of uninterrupted focus.¹ Importantly, interruptions are not isolated events; they accumulate and create ongoing reorientation costs as users attempt to resume previous tasks.

From a UX perspective, I think this reframes the role of notifications. Rather than happening in more stable contexts, notifications enter environments where users are already managing multiple cognitive threads. Each interruption forces users to suspend their current task, encode it’s state into memory¹, attend to new information then later reconstruct the previous context. This process increases cognitive load and contributes to stress and reduced task efficiency.¹

I think that this finding directly challenges notification systems that assume users are always available or inactive. Designing notifications without accounting for fragmented work environments risks applying cognitive strain rather than supporting task continuity.

Removing notifications: productivity versus emotional cost

Pielot and Rello’s “Do Not Disturb” field experiment provides a focused lens on the consequences of push notifications. In their study, participants disabled notification alerts for 24 hours across devices and reported their experiences compared to a baseline day.²

The results reveal a clear tension. Participants reported higher perceived productivity and reduced distraction without notifications. At the same time, they experienced increased anxiety about missing important information and feelings of social disconnection. Notifications therefore serve a dual role: they disrupt focused work, yet they also function as signals of social presence and availability.

Table 1 : Statistical analysis of the responses to the questionnaires that were filled out after the days with and without notifications.²

For interaction design, this highlights that notifications are not merely informational triggers. They shape users’ sense of responsiveness and feeling of obligation to connect. Eliminating notifications entirely is not a viable solution; instead, systems must negotiate between cognitive efficiency and social expectations.

The study also introduces an important systemic concern. When users experience notification overload, they tend to disable notifications broadly rather than selectively. Pielot and Rello describe this as a “Tragedy of the Commons,” where individual applications compete for attention, leading users to withdraw from the notification ecosystem altogether.² This has long term implications for both usability and trust.

Attention span myths and design justification

Bradbury’s critical review of attention span research addresses a common justification for aggressive notification strategies: the assumption that users inherently have very short attention spans. Bradbury demonstrates that widely cited claims, such as the “8-second attention span,” are often based on weak or misinterpreted evidence.³

He argues that attention is difficult to define, highly context-dependent and strongly influenced by content quality and delivery rather than fixed biological limits. For UX design, I think this is significant. When designers rely on oversimplified attention metrics, interruptions can be framed as necessary adaptations to human limitations rather than as design choices with consequences.

This perspective aligns with notification research that shows attention fragmentation is not inevitable but shaped by system behavior. Treating attention as limited source does not justify constant interruption. It places responsibility on designers to minimize unnecessary competition for it.

Design implications for notification systems

Across these studies, notifications emerge as a design “tradeoff” rather than a neutral feature. Research evidence consistently shows that poorly managed notifications can increase fragmentation, cognitive load and emotional strain while their complete removal introduces anxiety and social friction.

For interaction design, this can suggest several principles:

• Notifications should be designed as part of a broader attention system, not as isolated prompts.
• Interruption cost and resumption effort must be considered explicitly, especially in fragmented work contexts.
• Systems should support user agency in managing availability and responsiveness, rather than enforcing constant real-time interaction.
• Metrics such as open rates or immediacy should not override cognitive and emotional well-being.

Industry-oriented UX writing points out many of these points by advising for relevance, timing and restraint in notification design.^{4 5} However, I think without grounding in academic research, such guidelines can risk becoming optimization checklists rather than principled design strategies. The academic literature makes clear that notification design operates at the intersection of productivity, emotion and social norms and cannot be reduced to surface-level best practices.

Positioning within the broader research trajectory

Within the broader scope of my research project, notification experiments provide concrete evidence of how interruptions affect flow, recovery and user experience over time. They establish notifications as a critical case study for understanding interruption as a structural condition of contemporary interaction design.

References (APA 7)

1. Mark, G., Gonzalez, V. M., & Harris, J. (2005). No task left behind? Examining the nature of fragmented work. Proceedings of the SIGCHI Conference on Human Factors in Computing Systems, 321–330. https://doi.org/10.1145/1054972.1055017
2. Pielot, M., & Rello, L. (2017). Productive, anxious, lonely: 24 hours without push notifications. Proceedings of the 19th International Conference on Human-Computer Interaction with Mobile Devices and Services, 1–11. https://doi.org/10.1145/3098279.3098506
3. Bradbury, N. A. (2016). Attention span during lectures: 8 seconds, 10 minutes, or more? Advances in Physiology Education, 40(4), 509–513. https://doi.org/10.1152/advan.00109.2016
4. Warren, A. (n.d.). The fine art of notifications in UX. Medium. https://medium.com/@thatameliawarren/the-fine-are-of-notifications-in-ux-19a41a0b0c15
5. Interaction Design Foundation. (n.d.). How to design notifications for better mobile interactions. https://www.interaction-design.org/literature/article/how-to-design-notifications-for-better-mobile-interactions
   
   AI Assistance Disclaimer:
   AI tools were used at certain stages of the research process, primarily for source exploration, grammar refinement and structural editing. All conceptual development, analysis and final writing were made by the author.

I first encountered Mihaly Csikszentmihalyi’s work during my second bachelor’s degree in Game Design. We discussed his theories alongside the work of Johan Huizinga on play theory, specifically the idea that serious institutions often start as games or contexts for goal-directed action. Now, revisiting his work for this research, I want to focus on how relevant these psychological concepts are for general user experience (UX) and interaction design.

Defining Optimal Experience

As designers we often talk about “frictionless” experiences or engagement metrics. However, the psychological state we are actually aiming for is what Csikszentmihalyi calls “optimal experience”.³ In his research he defines flow as a state of concentration so focused that it amounts to absolute absorption in an activity.

It is a common misconception that this state is about relaxation or passivity. Flow actually occurs when a person’s body or mind is stretched to its limits in a voluntary effort to accomplish something difficult and worthwhile.⁴ People in flow typically feel strong, alert, in effortless control and unselfconscious. For interaction design this means we aren’t just trying to make things “easy.” We are trying to facilitate a specific type of intense engagement.

The Architecture of Flow in Design

What makes this theory so useful for my research is that Csikszentmihalyi deconstructs the conditions required to enter this state. He identifies several key elements that generate flow and some of them read almost like a checklist for good interface design:

• Clear Goals: The user must have a clear understanding of what needs to be done. In a digital system ambiguity is the enemy of flow.³
• Immediate Feedback: Action and awareness must merge. When a user acts the system must provide immediate feedback to confirm the action was successful.³
• Balance Between Challenge and Skill: This is perhaps the most critical component for my research. Flow requires a balance between the challenges perceived in a situation and the skills a person brings to it.³

If an interaction is too simple relative to the user’s skill the result is boredom. If the challenge is too high the result is anxiety. In my proposal I noted that games manage this balance well through adaptive difficulty but productivity software often fails here, stucked between boring repetition and frustrating complexity.

The Paradox of Work and Play

One of the most surprising insights I found in the readings is that flow actually happens more often at work than during free time. In an interview Csikszentmihalyi explained that this is because work is structured much more like a game than everyday life is. Work usually has the clear goals, rules and feedback loops that generate flow whereas unstructured leisure time can lead to boredom or apathy.¹

This is a crucial realization for my research into interruptions. When we design interactive systems we are essentially building a structure for the user’s attention. If we design these structures poorly or if we allow interruptions to shatter the structure we create “psychic entropy”, a state of disorder in consciousness where the self becomes impaired.³

Attention as a Limited Resource

To understand why interruptions are so damaging to this state we have to look at the biological limits of our attention. Csikszentmihalyi notes that the human nervous system has a limited capacity to process information, estimated at about 126 bits per second.² This infinite amount of “psychic energy” must be allocated carefully to accomplish any task. When we are in flow our attention is so fully invested in the activity that there is no psychic energy left over for distractions or even for the sense of self. A digital interruption forces the brain to reallocate this scarce resource, breaking the coherent order of consciousness and introducing “noise” into the system.

The Autotelic Nature of Experience

Ultimately the goal of understanding flow in design is to foster what Csikszentmihalyi calls “autotelic” experiences, activities that are worth doing for their own sake. The term comes from the Greek auto (self) and telos (goal), referring to a self-contained activity where the doing itself is the reward.⁵ In Interaction Design we often focus heavily on the output of a system, such as sending an email or finishing a report. However, Flow theory suggests that the process of interaction is just as important as the result. If we can design interfaces that transform necessary tasks into autotelic experiences we can turn potential sources of frustration into moments of order and enjoyment.

References

1. Beard, K. S. (2015). Theoretically Speaking: An Interview with Mihaly Csikszentmihalyi on Flow Theory Development and Its Usefulness in Addressing Contemporary Challenges in Education. Educational Psychology Review, 27(2), 353–364.
2. Cherry, K. (2023, March 23). Mihaly Csikszentmihalyi: The Father of ‘Flow’. PositivePsychology.com. https://positivepsychology.com/mihaly-csikszentmihalyi-father-of-flow/
3. Csikszentmihalyi, M. (1988). The flow experience and its significance for human psychology. In M. Csikszentmihalyi & I. S. Csikszentmihalyi (Eds.), Optimal experience: Psychological studies of flow in consciousness (pp. 15–35). Cambridge University Press.
4. Csikszentmihalyi, M. (2000). Flow: The Psychology of Optimal Experience. Harper & Row.
5. Peifer, C. (2012). Flow theory. In Encyclopedia of human behavior (2nd ed.). Elsevier. https://www.sciencedirect.com/topics/psychology/flow-theory

AI Assistance Disclaimer:
AI tools were used at certain stages of the research process, primarily for source exploration, grammar refinement and structural editing. All conceptual development, analysis and final writing were made by the author.

Background

In a world where digital tools shape almost every aspect of daily life, uninterrupted attention has become a scarce resource for user experience. Whether working on a document, attending an online lecture or simply watching a video, users are constantly interrupted by notifications, pop-ups and interface prompts. While these features are designed to inform or engage, they often lead to fragmented interaction experiences. Our devices or services demand responsiveness, but rarely provide space for focus.
This tension between engagement and distraction has turned into one of the central design challenges of our time. How can systems sustain the user’s sense of continuity in an age of constant interruption?

The psychological foundation of this issue lies in Flow Theory, introduced by Mihaly Csikszentmihalyi. Flow describes a mental state in which people become fully absorbed in an activity, experiencing deep concentration, clarity and enjoyment. In design contexts, flow translates into seamless user experiences where goals are clear, challenges match skill levels and feedback feels immediate. However, digital systems frequently break this rhythm. A notification arriving at the wrong moment or a forced software update, can instantly push a user out of flow. Even minor interruptions transforms into a cognitive burden, leading to fatigue, frustration and reduced task performance.

The Problem of Digital Interruption

Interruptions are not inherently negative. Some are necessary, such as reminders or alerts that prevent mistakes. Yet, the majority of digital interruptions are poorly timed, irrelevant, or overly demanding. They shift control away from the user, forcing attention to fragment across multiple contexts. Psychologically, every interruption requires cognitive order; the user must pause the primary task, process new information and later recall where they left off. Research in cognitive psychology refers to this as “resumption lag”, the mental cost of re-establishing task focus after being distracted.

The modern work environment amplifies these effects. On average, users switch digital tasks every “47 seconds”, often without completing the previous one. This continuous switching prevents the brain from reaching a deeper state of engagement. When digital systems are designed without regard for cognitive continuity, they silently erode attention over time. Instead of enhancing productivity, they generate anxiety and emotional exhaustion.

In contrast, some interactive systems, especially video games and movies, demonstrate how flow can be protected. Games use adaptive pacing, contextual pausing and clear progress indicators to support immersion. Even when interruptions occur, players can usually recover easily, thanks to consistent feedback and memory cues.

Research Focus

My research project aims to investigate how interaction design can manage interruptions more intelligently. The main question guiding my work is:
How can design strategies preserve user flow and support faster cognitive and emotional recovery after interruptions?

The research focuses on three interrelated aspects:

1. Understanding the psychological impact of interruptions. How do different types of disruptions: external (like notifications) and internal (like self-interruptions), affect users attention, emotions and sense of control?
2. Identifying design patterns for recovery. What interface elements, transitions or cues help users focus and continue smoothly after being interrupted?
3. Comparing domains of experience. What can productivity tools learn from entertainment systems, such as games or movies, which often handle interruptions gracefully?

The project draws from existing studies on attention, cognitive load and media psychology. For instance, Marotta and Acquisti (2018) found that even short digital interruptions can lower task performance by increasing cognitive load and emotional irritation. Similarly, Reinecke (2009) highlighted how interactive media can act as recovery spaces, offering emotional balance after periods of stress. Together, these insights suggest that recovery is not only a technical question but also an ethical and emotional one designers shape how users experience focus, fatigue and relief.

Relevance for Design

From a design perspective, this topic bridges psychology and user experience. Interaction design is not only about aesthetics or usability; it is also about shaping the rhythm of attention. The way we design transitions, notifications, or feedback loops determines whether an experience feels calm or chaotic.
In practical terms, exploring interruption and recovery can influence several design areas:

• Interface design: crafting non-intrusive, adaptive notifications and context-aware pausing.
• UX strategy: balancing engagement metrics with respect for user attention and mental well-being.
• System design: creating recovery cues such as “Continue where you left off” or visual markers that help users recall previous actions.
• Ethical design: addressing the moral responsibility of designers to avoid exploiting users’ attention for profit.

Recent examples show that large tech companies are beginning to integrate these principles. Apple’s “Focus Mode” and Microsoft’s “Focus Assist” both allow users to filter and schedule interruptions intentionally. These features represent early steps toward a design culture that values user agency and mental clarity. Yet, they remain optional features rather than integrated philosophies. My aim through this research is to understand how such mechanisms could be embedded at the core of interaction design, not just added later as fixes.

References

• Csikszentmihalyi, M. (1990). Flow: The Psychology of Optimal Experience. Harper & Row.
• Pattermann, J., Pammer, M., Schlögl, S., & Gstrein, L. (2022). Perceptions of digital device use and accompanying digital interruptions in blended learning. Education Sciences, 12(3), 215.
• Marotta, V., & Acquisti, A. (2018). Interrupting interruptions: A digital experiment on social media and performance. SSRN Electronic Journal. https://doi.org/10.2139/ssrn.3283951
• Reinecke, L. (2009). Games and recovery: The use of video and computer games to recuperate from stress and strain. Journal of Media Psychology, 21(3), 126–142. https://doi.org/10.1027/1864-1105.21.3.126
• Mark, G. (2023). Attention Span: A Groundbreaking Way to Restore Balance, Happiness and Productivity. Hanover Square Press.
• Nielsen Norman Group. (2022). How Notifications Impact User Attention and Task Focus. https://www.nngroup.com/articles/notifications-user-focus/
• Adobe Blog. (2024). Designing for Digital Well-being: When Less Screen Time Means Better UX. https://blog.adobe.com/en/publish/2024/01/17/designing-for-digital-wellbeing
• Medium. (2023). Calm UX: Designing Interfaces That Respect Human Attention. https://uxdesign.cc/calm-ux-designing-for-human-attention
  
  
  AI Assistance Disclaimer:
  AI tools were used at certain stages of the research process, primarily for source exploration, grammar refinement and structural editing. All conceptual development, analysis and final writing were made by the author.