Users judge every new design against mental templates assembled from thousands of old ones. Familiar controls put that training to work for you, so interfaces should look like what they are and behave like what they resemble. I explain which expectations to honor, and when an improvement is worth the relearning, through 7 principles from psychology and design: Jakob’s Law, mental models and schemata, least astonishment, representativeness, signifiers, mere exposure, and the M

AI can’t simulate human research participants yet, but it can help interviewers practice before meeting real users | AI answers can drain users’ cognitive budgets through several kinds of complexity | Let users type distant dates | Simplifying the NASA-TLX instrument for measuring task load |

Personalized AI doubles its odds of changing your mind | Real users reveal what synthetic users miss | AI summaries can bias users even when full information is available | Agentic video production cuts human oversight but raises costs | Missing feedback makes users doubt their actions | Consumers show little loyalty to AI services | Voice AI practice helps students speak up in class | Silence improves interviews | Master–detail split views halve navigation work

Marking mechanisms are the cheapest usability win on the web: a tap turns a fleeting encounter into a durable, refindable object. But marking serves three distinct jobs (evaluate, curate, retrieve) that designers keep mashing into a single overloaded button. Use a heart for likes, a star for favorites, and a flag for bookmarks. Marks travel a 3-stage journey (keep, manage, exploit), so plan for collections that grow into the thousands.

The flow state & UX | AI has reshaped creative jobs, and 70% of creatives now use it | The cost of AI drops 13× per year | Every extra option adds thinking time | Design the human–AI team as one unit | Proactive AI must time interruptions carefully | Satisfaction depends on expectations | Carousels are an experience lottery

Misleading information scent sends users boomeranging back to the search results | Forecasters keep underestimating AI, except in the physical world | Optimistic Asia adopts AI faster than the worried West | False alarms teach users to ignore real ones | The feedback that trains AI needs usability testing | Disabled buttons are a teachable moment | Users think with their bodies

Flow is the state of total absorption in which work feels effortless, time evaporates, and performance peaks. Its 3 preconditions (clear goals, immediate feedback, and a challenge matched to skill) translate directly into design requirements, and its two great enemies are latency and interruption.

Designers use AI most for ideation and least for finishing | Product managers benefit more from AI than designers | AI tutors as good as human experts but 918 times cheaper | Icons need text labels | Users must be able to halt an AI run | Easy-in, easy-out | Observe–Orient–Decide–Act (OODA)