DA0-002 Data Concepts and Environments Practice Question
Which THREE of the following are valid methods for handling missing data?
⚠ Common exam trap
Many candidates confuse 'handling missing data' with 'preprocessing steps'—sorting (Option D) is a data organization technique, not a valid method for dealing with missing values, and ignoring missing data (Option B) is often mistakenly considered acceptable in quick analyses, but it violates best practices for robust data science workflows.
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
✓
Using a placeholder like 'Unknown' for categorical data
Using a placeholder like 'Unknown' for categorical missing data preserves the dataset's structure and allows analysis to proceed without introducing statistical bias. This method is particularly valid for nominal data where the missing category can be treated as a distinct value, enabling downstream operations like one-hot encoding or frequency analysis without distorting the original distribution.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Using a placeholder like 'Unknown' for categorical data
Why this is correct
Placeholder is a valid approach.
- ✗
Ignoring missing values and proceeding with analysis
Why it's wrong here
Ignoring can lead to errors.
- ✓
Replacing missing values with the mean of the column
Why this is correct
Mean imputation is a standard technique.
- ✗
Sorting the data to bring missing values to the top
Why it's wrong here
Sorting does not handle missingness.
- ✓
Deleting rows with missing values
Why this is correct
Listwise deletion is a common method.
Go deeper
Related to this question
About these practice questions
Courseiva writes every DA0-002 question from scratch — 986 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. 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.