Research library
Original digests of studies and books, each with the question, method, findings, limitations — and a link to the source. Summaries, not substitutes.
Study digests
Premature inline validation hurts checkout UX
Live validation that fires while users are still typing measurably increases frustration and error rates; validate after field completion.
Google Research (Rodden, Hutchinson, Fu) · 2010HEART: metrics for user-centered products at scale
Five metric families — Happiness, Engagement, Adoption, Retention, Task success — operationalized through a goals → signals → metrics process.
Nielsen Norman Group · 2000Why you only need to test with 5 users
Five users uncover ~85% of the usability problems a test can find; additional users mostly re-observe known issues.
Book digests
Interviewing Users
The field manual for research interviews: framing, guides, question technique, field behavior and analysis — from someone who has run thousands.
Don Norman · 2013The Design of Everyday Things
The conceptual foundation of the field: affordances, signifiers, mapping, feedback, constraints, mental models, and human error as design failure.