DA0-002 Data Analysis Practice Question
A data scientist trains a regression model and observes high variance with low bias. Which technique is most appropriate to reduce variance?
⚠ Common exam trap
CompTIA often tests the misconception that reducing variance requires removing features or simplifying the model, but Ridge regularization is the correct technique because it penalizes coefficient magnitude without discarding predictors.
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
✓
Apply Ridge regularization
Ridge regularization (L2) reduces variance by adding a penalty term proportional to the square of the coefficients, which shrinks them toward zero without eliminating them. This directly addresses high variance (overfitting) by constraining the model's complexity, while low bias indicates the model fits the training data well. The regularization parameter λ controls the trade-off between bias and variance.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Apply Ridge regularization
Why this is correct
Ridge adds penalty to coefficients, reducing overfitting and variance.
- ✗
Increase polynomial features
Why it's wrong here
This would likely increase variance further.
- ✗
Use a smaller training set
Why it's wrong here
Smaller training set typically increases variance.
- ✗
Remove correlated features
Why it's wrong here
This may reduce variance but can increase bias; not the most direct method.
Go deeper
Related to this question
About these practice questions
One of 986 original DA0-002 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
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.