The Test Plan: Your Most Important Step
Master the test plan template: Evidence → Change → Behavior → Metric Impact.
The Planning Problem
Here's a stat that might surprise you: Most inconclusive test results come from poor planning, not bad luck. The test plan is your insurance policy against wasted time and resources.
Why Test Plans Matter
The Cost of Skipping Planning
Without a clear test plan, teams often realize mid-test that they're measuring the wrong thing, forgot to account for seasonality, or didn't collect necessary data. Result? Weeks of wasted runtime and no learnings.
A good test plan delivers four key benefits:
Forces Clear Thinking
Clarifies what you're testing and why before investing resources
Aligns Stakeholders
Gets everyone on the same page before engineering begins
Documents Hypothesis
Creates a record for future learning and iteration
Reduces Inconclusive Results
Catches critical issues upfront before they waste weeks
The Test Plan Template
Use this four-part framework for every test:
Evidence
Why should we run this test? What data, research, or insights support this?
Example: User research showed 35% of users abandon checkout because the form is too long (15 fields). Heatmaps show drop-off at the address section.
By [Test Change]
What specifically are we changing? Be precise.
Example: By reducing checkout form from 15 fields to 8 fields (removing optional fields and auto-filling shipping = billing).
We Expect [Behavior Change]
How will users behave differently? What specific behavior will change?
Example: We expect users to complete checkout faster and abandon less frequently because the form requires less cognitive load.
Resulting In [Metric Impact]
What metric will move and by how much? Be specific about success criteria.
Example: Resulting in a 10-15% relative increase in checkout completion rate (from 65% to 72-75%).
Complete Example
Evidence: User research + heatmap data shows form length causes 35% abandonment.
By reducing checkout form from 15 to 8 fields,
We expect users to complete checkout faster with less abandonment,
Resulting in 10-15% increase in checkout completion rate.
Want a Detailed Template?
For a comprehensive, step-by-step guide with additional sections covering statistical planning, segmentation, and rollout strategy, check out our complete test design template.
View Complete AB Test Design TemplateKey Takeaways
- ✓Test plans are your most important step-they prevent inconclusive results.
- ✓Use the four-part template: Evidence → Change → Behavior → Metric Impact.
- ✓Start with evidence-data, research, or insights that justify the test.
- ✓Be specific about expected impact-vague predictions lead to vague learnings.
- ✓Document everything before you start building.