What is a controlled experiment?
A controlled experiment involves comparing two or more groups that are identical in every way except for one factor – the independent variable. This is the variable we manipulate to see if it has an effect. The other groups serve as a control group, providing a baseline for comparison. By keeping all other factors constant, we can confidently attribute any observed differences in the dependent variable (the outcome we’re measuring) to the independent variable.
For example, a company may use a controlled experiment to test how changing the content of a CTA button affects click-through rates. By presenting one version to a test group and another to a control group under identical conditions, the company can determine the impact of the change.
How does controlled experiment work?
- Define the hypothesis: Start by identifying what you want to test and what you expect to happen.
Example: Changing the headline on our homepage will increase sign-ups by 10%. - Identify the variable: Choose a single factor to test, such as a headline, image, or pricing strategy.
- Create test and control groups: Divide your audience into two groups:
- The test group experiences the change.
- The control group interacts with the original version.
- Run the experiment: Present the variable to the test group while keeping everything else identical for both groups.
- Measure results: Use relevant metrics to compare the performance of the test and control groups.
Types of controlled experiments
In marketing, controlled experiments are essential for testing strategies and making data-driven decisions. Here are the most common types:
- A/B split testing: Compares two versions of a single variable (e.g., a webpage, email, or ad) to determine which performs better.
- Multivariate testing: Tests multiple variables simultaneously to understand how their combinations influence results.
- Geo testing: Tests marketing strategies by applying changes in specific geographic regions while keeping other areas as controls.
- Randomized Controlled Trials (RCTs): Customers are randomly assigned to different treatment groups to isolate the effect of a specific variable.
Why are controlled experiments important?
A controlled experiment is a great method for businesses that aim to make data-driven decisions. Here’s why they matter:
- Accurate insights: By isolating variables, you gain a clear understanding of their impact.
- Risk mitigation: Test changes on a smaller scale before implementing them widely, reducing the risk of negative outcomes.
- Informed decisions: Data from controlled experiments provides a solid foundation for strategy and planning.
- Clear cause-and-effect relationships: Understand exactly how a variable influences outcomes.
