Test Methodology

What is Test Design?

Test design is the systematic process of planning, conceptualizing and conducting tests to optimize websites, landing pages and marketing campaigns. In the SEO and CRO context, it's about making data-driven decisions and continuously improving.

A professional test design follows scientific methods and ensures that test results are valid, reliable and statistically significant. It forms the foundation for sustainable optimizations and measurable success.

Test Design Principles

001. Assumption Formation

Every test begins with a clear, measurable hypothesis. This should be specific, testable and relevant to business goals.

Example Hypotheses:

• "A green call-to-action button increases conversion rate by 15%"
• "Shorter forms reduce bounce rate by 20%"
• "Images of people increase dwell time by 30%"

002. Controlled Variables

Only one variable should be changed per test to identify clear causal relationships. All other factors must remain constant.

003. Representative Samples

The test group must be large enough to deliver statistically significant results. At least 1000 visitors per variant are recommended.

004. Random Assignment

Visitors must be randomly assigned to test groups to avoid bias.

Test Design Methods

Test Design Process

001. Identify Problem

Analyze your current metrics and identify improvement potential:

• Low conversion rate
• High bounce rate
• Low dwell time
• Poor mobile performance

002. Formulate Hypothesis

Based on data and best practices, develop a testable hypothesis:

• If we change the CTA color
• Then conversion rate increases
• Because the new color is more visible

003. Plan Test

Define all important parameters:

Test Parameters:

• Target audience and segmentation
• Test duration and sample size
• Primary and secondary metrics
• Success criteria and abort criteria
• Technical implementation

004. Create Variants

Develop test variants based on your hypothesis:

Design Principles:

• Brand consistency
• Clear visual hierarchy
• Mobile-first approach
• Accessibility standards
• Loading time optimization

005. Run Test

Start the test and monitor continuously:

Monitoring Checklist:

• ☐ Traffic distribution correct
• ☐ No technical errors
• ☐ Data quality ensured
• ☐ External factors documented
• ☐ Regular status checks

006. Analyze Results

Evaluate the data and draw conclusions:

Analysis Criteria:

• Statistical significance (≥95%)
• Practical relevance
• Confidence interval
• Secondary metrics
• Long-term effects

Important Test Design Metrics

Primary Metrics

• Conversion Rate: Proportion of visitors who perform the desired action
• Click-Through-Rate (CTR): Proportion of clicks on an element
• Bounce Rate: Proportion of visitors who leave after one page
• Revenue per Visitor (RPV): Average revenue per visitor

Secondary Metrics

• Dwell Time: Time visitors spend on the page
• Pages per Session: Number of pages visited
• Form Abandonment: Proportion of incomplete forms
• Mobile Performance: Loading times and usability on mobile devices

Common Test Design Mistakes

001. Too Small Samples

Tests with fewer than 1000 visitors per variant often don't deliver significant results.

002. Too Short Test Duration

Weekdays and seasonal effects can distort test results. Test for at least 2 weeks.

003. Too Many Variables

Changing multiple elements simultaneously makes it impossible to identify the cause of changes.

004. No Control Group

Every test needs an unchanged control group as reference.

005. Biased Interpretation

Results should be interpreted objectively and data-driven, not according to personal preferences.

Test Design Tools

Best Practices for Test Design

001. Test Continuously

Implement a test culture where continuous optimization takes place.

002. Document Everything

Record all test parameters, results and learnings.

003. Learn from Failures

Even negative results provide valuable insights.

004. Segment Your Tests

Different target groups can react differently.

005. Consider External Factors

Holidays, marketing campaigns and seasonal effects can influence test results.

Test Design for SEO

SEO-specific Tests

• Title Tag Optimization: Test different formulations
• Meta Description Tests: Optimize click-through rates from SERPs
• Structured Data: Measure impact on SERP features
• Internal Linking: Test different link strategies

CRO-specific Tests

• Destination Page Design: Optimize conversion rates
• Form Optimization: Reduce abandonment
• Checkout Process: Increase completion rates
• Call-to-Action Buttons: Increase click rates

Related Topics

• A/B Testing Fundamentals
• Conversion Rate Optimization
• Landing Page Optimization
• User Experience Testing
• Technical SEO Testing