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Feature Engineering &
Data Preparation
Enhancing Data for Better Model
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What is Data Preparation?
• The process of cleaning and transforming raw data into
a usable format.
• Prepares data for machine learning or analytics tasks.
Example: A dataset with missing prices and duplicate
entries in an e-commerce table must be cleaned before
model training.
+91-96400 01789
contact@accentfuture.com
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Steps in Data Preparation
Key Steps:
1. Data Collection
2. Data Cleaning
3. Data Integration
4. Data Transformation
5. Data Reduction
Example: Merging customer purchase history with web
clickstream data.
contact@accentfuture.com +91-96400 01789
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Introduction to Feature Engineering
What is Feature Engineering?
• Creating new features or modifying existing ones to improve model
accuracy.
• Combines domain knowledge and data intuition.
Example: Extracting “day of week” from a datetime column for a retail
sales model.
contact@accentfuture.com +91-96400 01789
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Types of Feature Engineering Techniques
Popular Techniques:
• Binning
• One-Hot Encoding
• Feature Scaling
• Interaction Features
• Polynomial Features
Example: Converting “City” column into one-hot encoded
features: Delhi → [1,0,0], Mumbai → [0,1,0], etc.
contact@accentfuture.com +91-96400 01789
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Handling Missing Values
Methods:
• Deletion (Drop rows/columns)
• Imputation (Mean, Median, Mode, KNN)
• Predictive Imputation
Example: Filling missing Age values in a dataset using median age per
occupation group.
contact@accentfuture.com +91-96400 01789
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Feature Selection Techniques
Why Feature Selection?
• Reduces overfitting
• Improves model performance
• Decreases training time
Techniques:
• Filter Methods (e.g., Correlation)
• Wrapper Methods (e.g., RFE)
• Embedded Methods (e.g., Lasso)
Example: Dropping highly correlated features to avoid
redundancy.
contact@accentfuture.com +91-96400 01789
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Real-World Example
Use Case:
Predicting Credit Card Default
• Data Prep: Handle outliers in income, impute missing
credit history
• Feature Engg: Create ratio of used credit to total limit,
flag for high-risk zones
Outcome: Improved prediction accuracy from 70% to 85%
contact@accentfuture.com +91-96400 01789
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Summary & Next Steps
Key Takeaways:
• Clean data is essential for reliable models
• Feature Engineering adds intelligence to data
• Both steps are iterative and domain-specific
contact@accentfuture.com +91-96400 01789
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Contact Details
contact@accentfuture.com ​
AccentFuture
+91-96400 01789

Feature-Engineering-and-Data-Preparation

  • 1.
    preencoded.png Feature Engineering & DataPreparation Enhancing Data for Better Model
  • 2.
    preencoded.png What is DataPreparation? • The process of cleaning and transforming raw data into a usable format. • Prepares data for machine learning or analytics tasks. Example: A dataset with missing prices and duplicate entries in an e-commerce table must be cleaned before model training. +91-96400 01789 contact@accentfuture.com
  • 3.
    preencoded.png Steps in DataPreparation Key Steps: 1. Data Collection 2. Data Cleaning 3. Data Integration 4. Data Transformation 5. Data Reduction Example: Merging customer purchase history with web clickstream data. contact@accentfuture.com +91-96400 01789
  • 4.
    preencoded.png Introduction to FeatureEngineering What is Feature Engineering? • Creating new features or modifying existing ones to improve model accuracy. • Combines domain knowledge and data intuition. Example: Extracting “day of week” from a datetime column for a retail sales model. contact@accentfuture.com +91-96400 01789
  • 5.
    preencoded.png Types of FeatureEngineering Techniques Popular Techniques: • Binning • One-Hot Encoding • Feature Scaling • Interaction Features • Polynomial Features Example: Converting “City” column into one-hot encoded features: Delhi → [1,0,0], Mumbai → [0,1,0], etc. contact@accentfuture.com +91-96400 01789
  • 6.
    preencoded.png Handling Missing Values Methods: •Deletion (Drop rows/columns) • Imputation (Mean, Median, Mode, KNN) • Predictive Imputation Example: Filling missing Age values in a dataset using median age per occupation group. contact@accentfuture.com +91-96400 01789
  • 7.
    preencoded.png Feature Selection Techniques WhyFeature Selection? • Reduces overfitting • Improves model performance • Decreases training time Techniques: • Filter Methods (e.g., Correlation) • Wrapper Methods (e.g., RFE) • Embedded Methods (e.g., Lasso) Example: Dropping highly correlated features to avoid redundancy. contact@accentfuture.com +91-96400 01789
  • 8.
    preencoded.png Real-World Example Use Case: PredictingCredit Card Default • Data Prep: Handle outliers in income, impute missing credit history • Feature Engg: Create ratio of used credit to total limit, flag for high-risk zones Outcome: Improved prediction accuracy from 70% to 85% contact@accentfuture.com +91-96400 01789
  • 9.
    preencoded.png Summary & NextSteps Key Takeaways: • Clean data is essential for reliable models • Feature Engineering adds intelligence to data • Both steps are iterative and domain-specific contact@accentfuture.com +91-96400 01789
  • 10.