UX design principles are basic truths, laws, or assumptions that embody the accumulated knowledge of the researchers and designers who came before us. They're grounded in the study of human cognitive and physical capabilities, and they serve as a foundation for every design decision, especially when you're solving a complex or unfamiliar problem.
Several principles address human capabilities directly. William Lidwell, Kritina Holden, and Jill Butler define four characteristics of accessible design: perceptibility, everyone can perceive the interface; operability, everyone can interact with it; simplicity, everyone can comprehend and use it; and forgiveness, people feel safe because most interactions are reversible. Consistency spans four types: aesthetic, functional, internal, and external. People should be able to rely on recognition rather than recall, recognizing something they've seen before is far less demanding than pulling it from memory. And reducing cognitive load means making navigation options highly visible, eliminating unnecessary elements, and chunking content logically.
These principles aren't abstract theory: they're the same reasons a familiar button placement feels safe to click, or an unlabeled icon feels risky to trust.
1: Violates consistency. Different button placement across tools breaks both internal consistency (within the intranet as a system) and external consistency (with users' expectations from other software). People can't transfer what they've learned in one tool to the next.
2: Violates accessibility. Removing text labels without any alternative fails the perceptibility characteristic, not everyone can reliably interpret an unlabeled icon. This is a direct accessibility failure, not just a stylistic choice.
3: No violation, follows good practice. This decision directly reflects the guidance to reduce cognitive load by making navigation options highly visible. Live match counts and visible key links both support this principle rather than undermine it.
4: Violates reducing cognitive load. Forty ungrouped links on one page is the opposite of chunking content logically, one of the three explicit actions called out for reducing cognitive load.
Decision 2 is worth sitting with longer. Beyond the accessibility failure, it also violates recognition over recall: people should be able to rely on recognizing elements they've encountered before rather than pulling meaning from memory. A labeled icon lets someone recognize "Search" at a glance. An unlabeled magnifying-glass icon forces them to recall what that specific icon means in this specific tool, a small tax that adds up every time they use it, and one that experienced users pay just as much as new ones.