User research grounds design decisions in evidence rather than assumption. Qualitative methods answer why and how questions through rich, small-sample techniques like interviews, contextual inquiry (observing users in their natural environment), diary studies (capturing longitudinal behavior), and think-aloud protocols during usability testing. Quantitative methods answer what and how many questions through larger-sample techniques like surveys, analytics, and A/B testing. Triangulation combines multiple methods to increase confidence in findings, while affinity diagramming organizes observations into themes during synthesis. User personas synthesize research into fictional but realistic representations of target users, capturing demographics, goals, behaviors, and pain points. User journey maps visualize the process users follow to accomplish goals, including touchpoints, emotions, and pain points across the experience.
Usability testing observes real users interacting with a product to identify problems and validate decisions. Moderated sessions let researchers probe deeper in real time, while unmoderated sessions scale more easily and reach diverse participants remotely. Guerrilla testing offers rapid, informal feedback in public spaces. Tree testing validates information architecture by having users locate items in a text-only hierarchy, and first-click testing predicts task success by checking whether users' initial clicks head in the right direction. The System Usability Scale (SUS) provides a quick ten-item questionnaire that yields a comparable usability score, while task success rate and time on task offer more granular performance metrics. Eye tracking validates visual hierarchy by showing where users actually look, and heatmaps reveal click, tap, and gaze patterns across a page.
Metrics translate user experience into business-relevant signals. Conversion rate measures the percentage of users completing desired actions, while funnel analysis tracks drop-off at each stage of sequential flows like checkout. Retention rate captures the percentage of users returning after first use (often measured at Day 1, Day 7, and Day 30), with churn rate as its inverse. Daily Active Users (DAU) and Monthly Active Users (MAU) gauge engagement, and the DAU/MAU ratio indicates stickiness. Customer satisfaction (CSAT), Net Promoter Score (NPS), and Customer Effort Score (CES) measure subjective experience. A/B testing compares two design variants on measurable outcomes, but requires careful attention to statistical significance, adequate sample size, and patience to avoid the winner's curse and novelty effects that distort early results. Continuous discovery keeps research ongoing throughout product development rather than confining it to a single upfront phase.