# Why the details are invisible · Introduction The best interaction work is the work you cannot see. That is a problem for anyone trying to learn it. ### No science, only digging Rauno Freiberg opens [Invisible Details of Interaction Design](https://rauno.me/craft/interaction-design) by admitting that design can feel like there is no science to it, and that even researchers treat interaction design as a black box. Searching the web yields recycled content about personas and Venn diagrams. The substance reveals itself only “to those willing to fanatically dig for them,” in long research papers or by replaying hundreds of slow motion screen recordings. His method: make something, fill your head with the problem, go for a walk. ### Invisible on purpose A gesture that retains momentum, a menu that skips animation because you open it a hundred times a day, a loupe that disappears when your finger no longer covers the caret: each is a decision made so you would not have to think. Emil Kowalski, in [Building a Toast Component](https://emilkowal.ski/ui/building-a-toast-component): “Not all of these details are noticed by the user, but that’s okay. These details add up.” He borrows Paul Graham’s line about unseen details combining “like a thousand barely audible voices all singing in tune.” Source Jim Nielsen, The Unseen Work of Design (2021): the finished product is the outside perception of design; the process of getting there is what constitutes it. ### Take it apart If you cannot learn the work by looking at finished products, you take them apart. Freiberg closes his essay with the observation that articulating why something feels right “does not come as intuitively as designing something to feel right. But they are two sides of the same coin.” Analysing beyond “it feels nice” is what nurtures taste. Kowalski’s method is the same: two versions side by side, pick one, say why. That is this book’s method. Each chapter takes work by people who did the digging, quotes them where wording is the point, and puts a figure next to the prose so you operate the idea instead of reading about it. Where a number appears, a source states it (a 0.05 scale step per stacked toast, a 300 millisecond rule of thumb, a 90 to 10 split between familiar and novel). Where no source states one, none appears. Bartosz Ciechanowski, whose articles are read in [Explaining with interaction](https://learn-ui.com/chapters/explaining/explorable-explanations), is the proof of the premise: an explanation you can drag teaches something a diagram cannot.