Glossaries
Between Subjects Design
What is Between Subjects Design in User Research?
Between Subjects Design is a research method in user studies where different groups of participants are exposed to different conditions or variations of a product, with each group only experiencing one condition.
Synonyms: Independent Measures Design, Randomized Controlled Trial, Parallel Groups Design
How Between Subjects Design Works in User Research
Between Subjects Design is a fundamental approach in user research where researchers divide participants into separate groups, with each group experiencing a different condition or version of a product. This method allows researchers to compare the effects of different variables without the risk of carryover effects that can occur in within-subjects designs.
Benefits of Using Between Subjects Design
- Eliminates order effects: Participants are only exposed to one condition, preventing biases from previous experiences.
- Reduces fatigue: Shorter test sessions as participants only interact with one version.
- Ideal for testing major design changes: Allows for clear comparisons between significantly different designs.
- Minimizes learning effects: Participants don't become familiar with the task or interface over multiple conditions.
Examples of Between Subjects Design in UX Research
- Testing two different navigation layouts: Group A uses a hamburger menu, while Group B uses a tab bar.
- Evaluating onboarding experiences: Group A receives a guided tour, while Group B explores independently.
- Comparing pricing models: Group A sees a monthly subscription option, while Group B sees an annual plan.
Frequently Asked Questions
- What's the main difference between Within Subjects and Between Subjects Design?: In Within Subjects Design, all participants experience all conditions, while in Between Subjects Design, each group experiences only one condition.
- How many participants do I need for a Between Subjects Design study?: You typically need more participants than in a Within Subjects Design, as each condition requires its own group. A general rule is at least 15-30 participants per condition.
- When should I choose Between Subjects Design over Within Subjects Design?: Choose Between Subjects when you want to avoid learning effects, when testing conditions that can't be easily reversed, or when you're comparing significantly different designs or experiences.