Trunk Test
A usability test by Steve Krug that checks whether a user dropped onto any page of a site can instantly identify where they are, what the site is, and what they can do there.
Also known as: Krug's Trunk Test
Category: Techniques
Tags: usability, user-experience, evaluation, heuristics, interfaces, navigation, information-architecture
Explanation
The Trunk Test is a quick usability heuristic introduced by Steve Krug in *Don't Make Me Think*. The name comes from a vivid thought experiment: imagine someone blindfolded you, bundled you into the trunk of a car, drove you around, then dropped you in front of a random page on a website. When you open your eyes, could you answer a handful of essential orientation questions at a glance?
**The Core Questions**:
1. **What site is this?** (site ID)
2. **What page am I on?** (page name)
3. **What are the major sections of this site?** (primary navigation)
4. **What are my options at this level?** (local navigation)
5. **Where am I in the scheme of things?** (indicator like breadcrumbs or highlighted section)
6. **How do I search?**
If a user cannot answer all six within a few seconds, the page fails the Trunk Test — meaning its information architecture, navigation, or visual hierarchy is not working.
**How to Run the Test**:
- Print out (or take a screenshot of) a random page from deep inside the site.
- Hold it at arm's length or squint so only the dominant elements register.
- Circle the element that answers each of the six questions.
- If any answer is missing, unclear, or hard to find, that is a usability problem to fix.
**Why It Works**:
Users rarely arrive on a homepage via a neatly guided tour. They land on deep pages from search results, social links, or notifications — exactly the "dropped from a trunk" scenario. The test forces designers to stop assuming user context and to check whether every page can stand on its own.
**When to Apply**:
- Reviewing an existing site for navigation and information architecture issues.
- Evaluating new designs before launch.
- Auditing landing pages that receive traffic from ads, search, or referrals.
- Comparing your site to competitors using the same test.
The Trunk Test is cheap, fast, and brutally honest — it surfaces problems that heavy analytics or long testing sessions often miss, and it rewards the designer choices that make a site feel effortless to use.
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