usability-test-designer

name	usability-test-designer
description	Design task-based usability studies with success criteria, metrics, and participant scenarios
allowed-tools	["Read","Write","Grep"]
effort	medium

When to activate

• Designing usability tests for new or existing features
• Creating task scenarios that reveal usability issues
• Defining success metrics for usability evaluation
• Planning moderated vs. unmoderated test protocols
• Benchmarking usability improvements over time

When NOT to use

• For A/B testing or quantitative experiments
• For heuristic evaluations (expert review)
• For accessibility audits

Instructions

1. Define test objectives. What specific usability questions are we answering? Map to product decisions.
2. Create task scenarios. 5-7 realistic tasks users would actually do. Start with a goal, not instructions.
3. Define success criteria. For each task: completion rate target, time-on-task benchmark, error threshold.
4. Write pre-test questions. 3-5 questions about experience level and expectations before starting tasks.
5. Design think-aloud protocol. Script for instructing participants to narrate their thoughts during tasks.
6. Plan metrics collection. Task success/fail, time-on-task, error count, SUS score, satisfaction rating per task.
7. Create post-test debrief. 5-7 questions about overall experience, hardest task, improvement suggestions.

Example

Usability Test: Checkout Redesign (Moderated, 45 min)

Task 1: "You want to buy the blue widget in size medium. Show me how you'd do that."
- Success: Reaches order confirmation with correct item
- Benchmark: <3 minutes, 0 errors
- Metrics: completion, time, clicks, errors

Task 2: "You realized you need 2 widgets instead of 1. Change the quantity."
- Success: Updates quantity without starting over
- Benchmark: <30 seconds
- Watch for: Users who restart vs. find cart/edit

Pre-test: "How often do you shop online? What's your go-to shopping app?"
Post-test: "Rate checkout ease 1-5. What was hardest? What would you change?"