Graded Quiz Lesson 2: From Modeling to Evaluation :Data Science Methodology (IBM Data Science Professional Certificate) Answers 2025
1️⃣ Question 1
What is the main purpose of data modeling in the data science methodology?
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✅ To develop models for descriptive or predictive purposes
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❌ To refine and adjust the problem statement
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❌ To select an analytical approach
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❌ To collect raw data
Explanation:
Modeling focuses on building descriptive or predictive models that answer the business problem.
2️⃣ Question 2
How does a training set contribute to predictive modeling?
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❌ Helps select algorithms
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✅ A training set serves as a calibration gauge for the model
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❌ Contains variables not required
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❌ Provides unknown outcomes
Explanation:
The training set teaches (calibrates) the model how to recognize patterns and relationships.
3️⃣ Question 3
Primary purpose of model evaluation?
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✅ To assess the quality of the model and ensure it meets the initial request
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❌ Determine parameter values
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❌ Refine data collection
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❌ Deploy the model
Explanation:
Evaluation verifies whether the model appropriately solves the defined business problem.
4️⃣ Question 4
Purpose of diagnostic measures during model evaluation?
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❌ Refine model design
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❌ Ensure model is functioning
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❌ Assess descriptive relationships
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✅ To test the model’s statistical significance
Explanation:
Diagnostic measures in evaluation check how statistically reliable and valid the model is.
5️⃣ Question 5
What does the ROC curve help determine?
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❌ Statistical significance
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❌ Optimal model based on diagnostics
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✅ The true-positive rate and false-positive rate for different criteria
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❌ Misclassification cost
Explanation:
The ROC curve evaluates classification performance by showing the tradeoff between TPR and FPR.
🧾 Summary Table
| Q | Correct Answer | Key Concept |
|---|---|---|
| 1 | Develop descriptive/predictive models | Purpose of modeling |
| 2 | Training set calibrates model | Role of training data |
| 3 | Assess model quality | Model evaluation |
| 4 | Test statistical significance | Diagnostic measures |
| 5 | TPR vs FPR | ROC curve use |