Usability Testing
Plan and run lean usability studies—fake doors, Wizard of Oz, or prototype tests—before you commit production engineering to the wrong UX.
Overview
Usability testing is an agent skill most often used in Validate (also Idea and Build) that helps solo builders design and run effective usability studies from fake-door checks through prototype sessions.
Install
npx skills add https://github.com/refoundai/lenny-skills --skill usability-testingWhat is this skill?
- Four-step flow: clarify goal, choose fidelity, design the test, plan iteration back into product work
- Covers fake door, smoke, Wizard of Oz, and production testing fidelity choices
- Frames recruiting and scenarios around small-sample friction discovery (e.g. ~10 participants)
- Grounded in frameworks attributed to 11 product leaders in the skill narrative
- Use when planning user tests, prototype validation, or diagnosing why users struggle
- Four-step help flow: goal, fidelity, test design, iteration planning
- Frameworks and insights drawn from 11 product leaders per skill description
Adoption & trust: 1.4k installs on skills.sh; 1k GitHub stars; 3/3 security scanners passed (skills.sh audits); trending (+100% hot-view momentum).
What problem does it solve?
You are about to build or ship a flow but have no disciplined plan to watch real people struggle with it, so you risk coding the wrong experience.
Who is it for?
Founders validating prototypes, onboarding, or conversion paths with limited budget who want structured qualitative tests before heavy engineering.
Skip if: Teams that only need quantitative analytics dashboards, formal HIPAA-grade clinical trials, or fully automated experiment platforms with no user sessions.
When should I use this skill?
Planning user tests, designing prototype validation, preparing usability studies, or understanding why users struggle with the product.
What do I get? / Deliverables
You leave with a chosen test fidelity, scenarios, recruiting approach, and an iteration loop so findings feed the next build or scope cut—not a one-off report.
- Test plan with goal, fidelity choice, scenarios, and observe list
- Iteration notes tying findings to product changes
Recommended Skills
Journey fit
Spans multiple journey phases - primary shelf plus alternate fits below.
Prototype validation is the first moment builders need structured usability methodology; the skill shelves here even though findings also inform Build and Launch. Prototype subphase fits concept and fidelity decisions (smoke tests, facades) that the skill explicitly teaches before full build-out.
Where it fits
Choose Wizard of Oz fidelity so users see a working inbox facade while you manually fulfill actions behind the scenes.
Run a fake door on a landing CTA to see if the promised workflow resonates before scoping the MVP.
Re-test a redesigned checkout after build changes to confirm earlier friction points are gone.
Sanity-check a new onboarding path with five targeted users before pushing paid acquisition.
How it compares
Use for human-centered test design and fidelity choice, not instead of analytics stacks or automated split-test tooling.
Common Questions / FAQ
Who is usability-testing for?
Solo and indie builders who need to validate UX and value props with real people—especially before writing production code or after seeing confusing drop-off.
When should I use usability-testing?
In Validate when planning prototype or fake-door studies; in Idea when testing positioning with smoke tests; in Build when re-testing after a redesign; and in Launch when checking whether new flows are understandable before scaling distribution.
Is usability-testing safe to install?
The skill is planning and methodology guidance without destructive automation; review the Security Audits panel on this Prism page before installing any skill from the open ecosystem.
SKILL.md
READMESKILL.md - Usability Testing
# Usability Testing Help the user conduct effective usability testing using frameworks and insights from 11 product leaders. ## How to Help When the user asks for help with usability testing: 1. **Clarify the goal** - Determine if they're validating a concept, finding friction points, or optimizing conversion 2. **Choose the right fidelity** - Help them select between Wizard of Oz tests, fake doors, prototypes, or production testing 3. **Design the test** - Guide them on recruiting users, creating scenarios, and what to observe 4. **Plan for iteration** - Discuss how findings will flow back into the product development process ## Core Principles ### Fake it before you build it Itamar Gilad: "Initially you fake it - fake door test, smoke test, Wizard of Oz tests. We showed the tabbed inbox working to people, but it wasn't really Gmail, it was just a facade." Validate core value propositions before writing production code using faked versions where humans perform the automated task behind the scenes. ### Small samples reveal big friction Melanie Perkins: "It's amazing how you can find 10 random people on the internet and they can give such astute feedback that's so representative for such a large number of people." Run tests with as few as 10 random people to identify core product issues. ### Watch users, don't just ask them Uri Levine: "Simply watch users and see what they're doing. If they're not doing what you expect, then ask them why." Direct observation reveals behaviors and needs that surveys miss. Ask 'why' when users deviate from the expected path. ### Test multiple options, not one Kristen Berman: "We never do a UX study where we're just showing people one thing. We always present multiple options and relatively look for which one drives the intended behavior." Single-design testing is ineffective for predicting behavior. ### Overcome creator bias Guillermo Rauch: "You tend to overrate how well your products work. It's very important to give your product to another person and watch them interact with it." Directly observing users helps overcome the tendency to think your product is more intuitive than it is. ### Micro-level testing drives millions Judd Antin: "We changed seven characters and made Airbnb millions of dollars because we found out the button felt scary." Don't dismiss usability testing as junior work; finding scary or confusing CTAs can massively impact conversion. ### Progress through testing stages Itamar Gilad: "Mid-level tests are about building a rough version - early adopter programs, alphas, longitudinal user studies, and fish food (testing on your own team)." Use a progression from fish fooding to dogfooding to alphas to increase confidence iteratively. ### Make testing a team sport Noah Weiss: "We had PMs, engineers, designers, and the user researcher all in one Slack thread live, responding and reacting to the usability session." Increase engagement by having cross-functional teams live-react to sessions in shared chat threads. ## Questions to Help Users - "What specific behavior are you trying to observe or validate?" - "Do you need to validate the concept (use fake doors) or optimize the execution (use the real product)?" - "How will you recruit users who have 'zero skin in the game' for honest feedback?" - "Are you testing one option or multiple options to compare?" - "What will you do with the findings - how will they flow back into development?" - "Who else on the team should observe these sessions?" ## Common Mistakes to Flag - **Testing only one design** - Present multiple options to measure relative performance - **Building before validating** - Use Wizard of Oz or fake door tests before writing production code - **Re