DA0-002 Data Concepts and Environments Practice Question
A telecommunications company is experiencing issues with its customer satisfaction survey data. The data is collected from multiple channels: phone, email, and web forms. Each channel uses a different scale for ratings: phone uses 1-10, email uses 1-5, and web uses 1-7. Additionally, some survey responses contain missing values for demographic fields. The data analyst needs to calculate an overall satisfaction score that is comparable across all channels. The company's leadership wants a single metric that minimizes distortion from the different scales. Which approach should the analyst use to standardize the ratings?
⚠ Common exam trap
Watch out — candidates often think simple multiplication (Option D) is sufficient for scale conversion, but the understanding that linear scaling without considering the full range and distribution can introduce distortion is key, whereas min-max normalization is the proper technique for creating a comparable metric across different scales.
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
✓
Normalize each rating to a 0-100 scale using min-max normalization.
Min-max normalization rescales each rating to a common 0-100 range using the formula (x - min) / (max - min) * 100. This preserves the relative distribution of responses within each channel while eliminating the effect of different scale lengths, making the scores directly comparable. It minimizes distortion better than simple multiplication or binary conversion, as it accounts for the full range of each original scale.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Normalize each rating to a 0-100 scale using min-max normalization.
Why this is correct
Correct: Min-max normalization maps each scale to a common range, preserving relative differences.
- ✗
Calculate the average rating separately for each channel and then compare the averages.
Why it's wrong here
Incorrect: Averages are not directly comparable due to scale differences.
- ✗
Convert all ratings to a binary metric of satisfied (above midpoint) or unsatisfied.
Why it's wrong here
Incorrect: Binning loses information about degree of satisfaction.
- ✗
Convert all ratings to a 1-10 scale by multiplying email ratings by 2 and web by 1.43.
Why it's wrong here
Incorrect: This linear conversion assumes proportional intervals, which may not be valid.
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.