DA0-002 Data Acquisition and Preparation Practice Question
During a data mining project, an analyst discovers that a significant number of records have a negative value for the age field. What is the most appropriate first step?
⚠ Common exam trap
The trap here is that candidates often jump to data cleaning techniques like imputation or removal without first verifying whether the anomaly is a data quality issue or a legitimate value, which the DA0-001 exam tests by emphasizing the investigative step as the most appropriate first action.
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
✓
Investigate the source system for data entry errors.
The first step in handling anomalous data like negative ages is to investigate the source system for data entry errors. This aligns with the data mining process, where understanding the root cause of data quality issues is critical before applying any imputation or removal techniques. Without investigation, you risk masking systemic problems that could affect all records.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Impute using regression.
Why it's wrong here
Regression imputation is premature without understanding the data quality issue.
- ✗
Replace negative age with the mean age.
Why it's wrong here
Imputation should follow root cause analysis to avoid masking data quality problems.
- ✓
Investigate the source system for data entry errors.
Why this is correct
Determining why negative ages occur enables targeted correction and prevents future errors.
- ✗
Remove all records with negative age.
Why it's wrong here
Removing data without investigation can discard valuable information and hides underlying issues.
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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.