AI0-001 Implementing AI Solutions Practice Question
A data scientist is preparing a dataset for training a customer churn prediction model. To prevent train/test leakage, which TWO practices should be followed? (Select TWO)
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
✓
Split the data chronologically (e.g., use data before a certain date for training, after for testing)
To prevent leakage, time-based splitting respects temporal order (no future data in training). Not normalizing before splitting avoids information from the test set influencing training. The other options either cause leakage or are unrelated.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Remove duplicate records only from the test set to ensure uniqueness
Why it's wrong here
Removing duplicates only from the test set could introduce bias; deduplication should be done consistently across the whole dataset.
- ✗
Shuffle the entire dataset randomly before splitting into train and test sets
Why it's wrong here
Random shuffling before splitting can cause leakage if the data has temporal dependencies; it ignores time order.
- ✓
Split the data chronologically (e.g., use data before a certain date for training, after for testing)
Why this is correct
Chronological splitting preserves the temporal order, preventing future data from leaking into the training set.
- ✗
Normalize numerical features using statistics computed on the entire dataset before splitting
Why it's wrong here
Normalizing on the full dataset leaks information from the test set into the training set; normalization should be fit on training data only.
- ✓
Perform feature selection using only the training data, then apply the same features to the test set
Why this is correct
Feature selection should be done within the training set to avoid leakage; applying the same selection to the test set is fine as long as the selection process didn't see the test data.
About these practice questions
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This AI0-001 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 AI0-001 exam.