DA0-002 Data Analysis Practice Question
A data analyst is preparing to run an A/B test comparing two email subject lines. Which TWO of the following should the analyst define before the test begins?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The null and alternative hypotheses
Before A/B testing, define null and alternative hypotheses, and determine sample size needed for desired statistical power and effect size.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The exact lift in conversion rate
Why it's wrong here
Lift is measured after the test, not pre-specified exactly.
- ✗
The time series decomposition
Why it's wrong here
Time series decomposition is unrelated to A/B testing.
- ✗
The p-value after the test
Why it's wrong here
P-value is computed from the data, not predefined.
- ✓
The null and alternative hypotheses
Why this is correct
Needed to frame the test and interpret results.
- ✓
The sample size required for the desired power
Why this is correct
Sample size calculation ensures the test can detect an effect if it exists.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DA0-002 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DA0-002 exam.