DA0-001 Comparing and Contrasting Data Concepts Practice Question
This DA0-001 practice question tests your understanding of comparing and contrasting data concepts. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Exhibit
Refer to the exhibit.
Exhibit:
Table: Customer_Master
Column: Email_Address
Completeness: 92%
Validity: 85%
Uniqueness: 97%
Consistency: 100%
Refer to the exhibit. Which conclusion can be drawn from this data quality report?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The Email_Address column has a high uniqueness rate but needs improvement in validity.
Option A is correct because the data quality report shows that the Email_Address column has a high uniqueness rate (e.g., 100% unique values), indicating no duplicate entries, but a low validity score (e.g., many entries fail format checks like missing '@' or domain). This means the column is structurally unique but contains invalid data, so it needs improvement in validity.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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 Email_Address column has a high uniqueness rate but needs improvement in validity.
Why this is correct
Uniqueness is 97%, but validity is only 85%, meaning some emails may be in invalid format.
Related concept
Read the scenario before looking for a memorised answer.
✗
The column is fully consistent but has low completeness.
Why it's wrong here
Completeness is 92%, which is not low; consistency is 100%.
✗
The column has low validity and low uniqueness.
Why it's wrong here
Uniqueness is 97%, which is high, not low.
✗
The column requires immediate action to improve completeness.
Why it's wrong here
Completeness at 92% is generally acceptable and may not require immediate action.
Common exam traps
Common exam trap: answer the scenario, not the keyword
CompTIA often tests the distinction between uniqueness and validity, trapping candidates who assume high uniqueness implies high quality, when in fact validity is a separate dimension that can be poor even with perfect uniqueness.
Detailed technical explanation
How to think about this question
In data quality management, uniqueness measures the absence of duplicates (e.g., via COUNT(DISTINCT) vs. COUNT(*)), while validity checks against a format rule (e.g., regex for email: ^[\w.-]+@[\w.-]+\.\w+$). A column can be 100% unique yet have 50% invalid entries if all values are distinct but malformed, which is common in user-input fields without client-side validation.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the DA0-001 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Comparing and Contrasting Data Concepts — This question tests Comparing and Contrasting Data Concepts — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The Email_Address column has a high uniqueness rate but needs improvement in validity. — Option A is correct because the data quality report shows that the Email_Address column has a high uniqueness rate (e.g., 100% unique values), indicating no duplicate entries, but a low validity score (e.g., many entries fail format checks like missing '@' or domain). This means the column is structurally unique but contains invalid data, so it needs improvement in validity.
What should I do if I get this DA0-001 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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Question Discussion
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