Personal Design Theory
March 20, 2026
Jay Shim
Introduction
What exactly is good design to…me?
Since beginning my journey into the world of design, I’ve found myself consistently returning to that one ambiguous question. It’s led me to become hyper-aware of why things are placed where they are, how they move, and what might've driven the thought process behind it all. Along the way, I’ve learned that design isn’t as simple as enlarging a button or relying on some vague notion of color psychology. Instead, it’s about how something…feels. Does it create a sense of warmth and familiarity - or does it feel cold and distant? To me, that’s what design is all about - capturing the right feeling of comfort and translating it into every interaction within a system.
To supplement my newly founded view, over the course of two weeks, I recorded my daily interactions with my most used hardware and software applications with scrutinizing attention. During this experiment, I quickly found that the most effective designs I engaged with had a positive correlation with the effort and speed in which I navigated them with or without extensive usage beforehand. More specifically, my interactions through my smartphone apps like Divvy, Spotify, and Apple Pay felt almost automatic. On the other hand, when something interrupted my mental flow for even just a moment instantly felt…bad.
From these observations, I developed a personal design philosophy grounded in clarity of system statuses, contextual responsiveness, and awareness of people's tendencies. Drawing from Don Norman’s concepts of affordances and feedback and Jakob Nielsen’s usability heuristics, I compiled a set of guidelines that reflect both established theory and my own personal anecdote.
Interaction Inventory
Physical Inventory
Electric Toothbrush (Philips Oral-B)
Initially a skeptic, I always thought electronic toothbrushes were born out of the trend of needless “tech” upgrades. After being gifted one for my birthday, I am now a religious user with my average usage of said device at twice daily (morning and night) everyday. This is one of my favorite pieces of hardware in my home because of it's renewable design and how effortless it makes the moderately tiring shoulder exercise that is brushing your teeth. The toothbrush has a vibrating head equipped with a timer that pulses every 30 seconds for each quadrant of your mouth, a replacement indicator for the brush head, full waterproof functionality, and one master button for all controls.
Bedroom Humidifier
I run my massive 3 liter humidifier everyday nightly during winter months even though it comes with a slew of problems. The water tank itself is not transparent - making it inconvenient to monitor the water level. Instead, the humidifier has a small button that lights up an LED in the interior. Refilling the water tank itself is an incredibly awkward and cumbersome task as the small opening requires careful pouring to avoid spills. Additionally, due to where the opening is located, maintenance (cleaning the base and filter) is time-consuming and tedious but necessary due to mineral buildup and odor. The only real positive design this humidifier boasts is the adjustable mist output knob which allows fine control of the mist strength…
Personal Laptop (Apple Macbook Pro 2018)
I rely on my laptop four to six hours daily for writing, research, and video calls. I've become accustomed to the stellar trackpad experience which utilizes intuitive gestures that I've even come to expect from other laptops. Some of the most natural feeling gestures being two‑finger scrolling and three‑finger workspace switching. My only complaint comes when needing to connect external devices. With only a few ports, I often need adapters for 3mm jacks, more USB-A ports, and an ethernet adapter. The design prioritizes minimalism over situational flexibility and user expectations.
Microwave Oven
I use my microwave to reheat or make food multiple times a day - primarily through the “Add 30 Seconds” shortcut button. Upon completion of cooking, the microwave generates an auditory signal to signify to me that cooking is finished. I'm so confident in this notification that I walk away to complete other tasks as the microwave cooks my food. Additionally, the microwave continues to make noise every 10 seconds if the door is not opened to remind me cooked food is still inside.
Digital Inventory
Divvy (Public Bike Share Phone Application)
I use this app around 10-12 times a month primarily to bike to my friends’ places when Uber rides are unaffordable and occasionally for recreation when the weather is nice. The user experience of this app is near perfect for me as it is feature rich (Full built-in real time navigation that encompasses bike reservation to biking path to bike docking station) yet also can be as simple as I want it to be (scan a bike and go). I also especially love that the app makes it easy to see the real-time availability of bikes docked near me. Occasionally, I do notice for myself and others (by observing strangers interactions) that unlocking the bikes themselves can be somewhat intuitive as there is a delay between when the app signifies that the unlock has occurred and the actual dock has unlocked the bike - leading to a lot of unnecessary yanking and frustration.
Smartphone Alarm (Apple IPhone 12 Pro)
I use my smartphone alarm every weekday at 7:00 a.m. Undoubtedly a time when my alertness and motor precision are at their lowest. I really love that the user interface features a massive and oversized “Snooze” button alongside an equally as massive “Stop” button directly under it. Uniquely, however, the stop button requires a swipe gesture to dismiss the alarm which I absolutely adore as it requires more effort and forcibly puts me in a more awakened state due to this necessary extra gesture. In a groggy state, I’ve triggered unintended actions quite a bit. But, in this case, I rarely ever sleep past my alarm.
Public Transit Card (Ventra Card via Apple Pay)
I use the bus here in Chicago quite a bit to commute between my apartment and the city. I use my transit card several times per week during peak hours. I love that usage of the card is incredibly clear. Double tap my phone's lock button to produce a digital card. Then, tap said digital card on the bus’ NFC touchpoint - a successful tap triggers haptics and a green tick mark and short beep appears on the touchpoint screen - whereas - insufficient funds or a failed scan produces a red X on the screen and a similar auditory cue. When it's crowded and noisy both the haptics and visual/auditory stimuli are incredibly helpful.
Spotify
Spotify is part of my daily routine during commutes, gym time, and study sessions. I love that the flow of using the app is incredibly simple - open the app, select a playlist, press play - almost no down time.
Personal Design Principles
1. Transparency
Users should never have to guess whether an action has been registered within its system. Great designs emphasize clear feedback to be instantaneous, distinct, and meaningful. This principle expands on Nielsen’s “Visibility of System Status” and Norman’s emphasis on “Feedback”. For example, Apple's smartphone alarm and Macbook trackpad provide effective immediate visual feedback when engaging with its buttons, sliders, and gestures through animations/haptics/sounds.
2. Stress Free
Good design should assume and understand distraction, fatigue, or stress. Larger targets and forgiving interactions support users when precise motor skills are limited. For example, the oversized snooze button makes engaging with the app less irritating and less stressful by increasing the target size of the buttons by a significant amount during low‑alertness moments.
3. Complexity Should Be Asked For
Functionality should unfold in stages or groupings - only revealing advanced options when needed or engaged with. For example, Spotify's core playback functions are kept at the forefront and ever present while keeping the ability to stream and share music to local devices deeper within the UI. This aligns with Nielsen’s heuristic of “Flexibility and Efficiency of Use.”
4. Robust
Design should not be formed off of the basis of planned obsolescence. Not only is planned obsolescence terrible for the environment - it is also incredibly unsatisfying to the consumer. Good design should understand longevity and make maintenance (cleaning, repair, and storage) easy.
5. Preserve Mental Models
People expect things to “work”. Once users develop habits and mental models towards certain systems - change introduces cognitive cost. Designs should practice empathy and intrinsically keep complexity to appropriate levels. Buttons should click. Slider should slide.
6. Uses As Many Of Our Senses
Good design should communicate and be accessible through multiple channels of - auditory stimuli, visual stimuli, and touch. These cues shape the basis of user perception and comfort whilst also making sure that the system is accessible for everyone. This principle draws from Norman’s emotional design framework, particularly the visceral level.
7. Recurrence
Key information and actions should be accessible through multiple screens or places within the system. For example, having a way to return to the landing page or search the system no matter where you are within the system.
Case Studies
Case Study 1: Spotify (Exemplary)
Interaction Context
I cannot stress how much I love using Spotify. I use Spotify almost everyday during all down times of my life - often one‑handed. Due to the way I hold my phone, the persistent bottom navigation bar in Spotify is not only convenient but also provides a stable orientation for holding my phone. I also love how all of the UI buttons have this little flare of animation to give me immediate feedback. Additionally, I also really appreciate the ability to create personalized playlists as they reduce decision time of what I want to listen to and increase my overall engagement with the platform.
Connection To My Principles
Transparency: The immediate icon change from play to pause with animations confirms action without ambiguity.
Complexity Should Be Asked For: Core playback controls are always visible - while advanced features such as queue editing, audio settings, and music sharing remain secondary.
Preserve Mental Models: Despite semi-frequent updates, the core navigation structure has remained nearly the same - supporting long‑term familiarity.
Stress Free: Personalized recommendations and curated playlists create a sense of recognition and comfort.
Overall, as an audio consumption platform, Spotify succeeds as an application simply because it minimizes friction while preserving user control and interest. Its design supports both quick, effortless, and habitual interactions while offering deeper functionality when desired.
Case Study 2: Bedroom Humidifier (Problematic)
Interaction Context
I use my bedroom humidifier nightly during the winter months to reduce dry throat or nasal irritation while sleeping. It does indeed serve its core function - adding moisture to the air, however, multiple design limitations reduce its overall usability. I keep it around just because it does its job - not because I enjoy using it. For starters, refilling the water tank is awkward - the incredibly small opening and heavy weight require careful handling which makes spills common. The power button placement is unintuitive - the button is fixed to the back making it hard to reach in all scenarios. Cleaning the water tank itself and its base is time-consuming with neglect leading to buildup and odor. There is no feedback at all for water levels. I have to visually monitor the water level with the built-in light - which can be inconvenient.
Connection To My Principles
Stress Free: Button placement confines it to certain locations due to accessibility and refilling process requires precision and attention from the user.
Robust: Cleaning and upkeep are cumbersome and time-consuming.
Recurrence: No way to check low water or malfunction other than through one button that displays light. What if the light eventually dies.
Suggested Improvements:
Distinct visual and auditory feedback: Use LED color changes or sounds to indicate low water, normal operation, or errors.
Accessible control placement: Move power/mist controls to the front or top for easy reach in low light.
Redesigned tank opening: Wider opening to simplify refilling and reduce spills.
Maintenance alerts: Integrate periodic cleaning reminders or filter change notifications.
Conclusion
Upon conclusion of this project (and much reflection), I find that I've walked away having developed a firmer understanding of what design is starting to look like to me - essentially an amalgamation of empathy, sympathy, and logic.
Through developing my own heuristics, I learned that design is something that is deeply emotional and so very human. It shouldn't be perfect - and never will be because of its intended target of use.
My definition of “design” is this: the feeling of comfortability and the minor satisfaction when something just works. When a system just organically supports what you need to do or want to do almost as naturally as moving an arm or a leg. That is, effective design should almost never demand attention to itself to the point in which it feels routine and…comfortable. I intend to encapsulate the “feeling of comfort”.
References
Nielsen, J. (1994, April 24). 10 usability heuristics for user interface design. Nielsen Norman Group.https://www.nngroup.com/articles/ten-usability-heuristics/
Norman, D. A. (2013). The design of everyday things: Revised and expanded edition. Basic Books.