Learning Objectives
By the end of this lesson you will be able to:
- Define the three components of a SBET session: charter, time box, and debrief
- Explain how session-based testing differs from both scripted testing and ad-hoc testing
- Describe what makes exploratory testing structured rather than random
The Problem With Two Extremes
Pure scripted testing gives you documentation and repeatability but produces no new knowledge — you test what you already thought to test, and miss everything you didn't anticipate.
Ad-hoc testing is fast and creative but leaves no trace — no one knows what was covered, what wasn't, or why a particular bug was found. It can't be repeated, reported, or improved.
Session-Based Exploratory Testing (SBET) is the middle path: the creativity of exploratory testing with enough structure to be manageable, reportable, and repeatable.
The Three Components
1. The Charter
A charter is a short statement of the session's mission. It answers: "What am I exploring, and what am I looking for?"
Format: "Explore [area] with [resources] to discover [information]"
Example: "Explore the promo code application logic with valid and edge-case promo codes to discover how the system handles boundary conditions and unexpected input formats."
A charter is focused but not prescriptive — it gives direction without dictating every step.
2. The Time Box
Sessions are time-limited. The standard is 60–90 minutes of uninterrupted testing. Within that window, you follow the charter but adjust based on what you discover.
Time-boxing serves two purposes:
- It creates accountability: you know what you'll deliver before you start
- It prevents rabbit holes: when something interesting appears, you note it and continue, rather than spending 3 hours on a tangent
3. The Debrief
After the session, you produce a structured summary:
- Bugs found: list with severity
- Issues observed: things that don't look right but aren't clearly bugs
- Test notes: what you covered, what you didn't
- Session metrics: estimated % of charter completed, time spent on bugs vs. exploration
Why This Is Structured Testing
SBET is not "do whatever you want for an hour." It is:
- Planned (you write the charter before starting)
- Bounded (you know when you'll stop)
- Documented (you produce a debrief)
- Improvable (reviewing your debriefs shows where you find the most bugs)
Pro Tip: Before a session, spend 5 minutes reviewing your anti-patterns checklist (Module 6) and deciding which categories are most relevant to your charter area. This primes your intuition and makes the exploration more targeted.
Session Metrics
Teams using SBET track:
- Session time: total hours of exploratory testing in a sprint
- Bug density: bugs found per session hour (improving over time means your technique is improving)
- Coverage: % of charter areas that received at least one session
These metrics make exploratory testing visible in project reporting — it stops being "testing that's hard to track" and becomes a measurable, manageable activity.
Summary
Session-Based Exploratory Testing gives free-form exploration a backbone: a charter to focus it, a time box to bound it, and a debrief to document it. In the next lesson, you'll learn to write the charter — the most important component of the three.