Feature Engineering: Enhancing Model Performance

Zunaira Kannwal
3 min readJun 21, 2024

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Feature extraction is one of the most central steps in the machine-learning process. In this step, raw data is manipulated and ready to assist it to be fit for modeling the problem into analytical models.

Imputation

Handling the missing values is crucial since most machine learning models cannot holder such values in their computations.

Numerical Imputation: Replace missing histories by substituting missing values with the variable’s mean, median, or mode value.

Categorical Imputation: Some missing values can be predicted using the most common category or adding a new class such as ‘Unknown’ or ‘Other’ (Built-In) (AITechTrend — Further into the Future).

Handling Outliers

Such observations going against the norm are predictable to affect the outcome while using models dependent on data distribution like linear reversion. Techniques include:

Removal: It only removes circumstances where one finds values too high or too low.

Capping: Limiting the number in a given cohort at a programmed percentile rating.

Transformation: This is done by using transformation methods such as put on log on the data or applying square root on the data to reduce the effect of the outliers. (Built-In) (Analytics Vidhya).

Feature Scaling

Normalization: Converting structures to relative forms of measurement ranging from 0 to 1.

Standardization: Normalizing the features to a mean equal to 0 and change equal to 1. Specifically, the Support Vector Machines and the K-Means bundling algorithms will benefit (AITechTrend — Further into the Future).

Encoding Categorical Variables

One-Hot Encoding: Converts all categorical structures into binary split features. For example, where a column might contain a range of replies encompassing Red, Green, and Blue, it creates three new columns with discrete reaction options of Red in the first column, Green in the second column, and Blue in the third column.

Label Encoding: It translates categories to integers and thus can present ordinal relationships that are really Built In (AITechTrend — Further into the Future).

Creating New Features

Interaction Features: Joining two or more facets to create a reasonable connection between them (for instance, with the help of multiplication or addition).

Polynomial Features: Increasing powers of the existing features to incorporate the non-linearity component (Analytics Vidhya).

Transformation Techniques

Log Transformation: Applied to reduce or eliminate right skewness.

Reciprocal Transformation: This means subtracting two numbers and converting the signs of large values to minor and vice versa.

Box-Cox and Yeo-Johnson Transformations: Other complex alterations capable of managing higher quantities of deliveries and values can be applied (Analytics Vidhya).

Automated Feature Engineering Tools

Feature tools: Pythons that are able to autonomously produce features from the relational and temporal data streams.

Scikit-learn: Enables multiple choices concerning the features to be included or excluded and how the structures are to be transformed.

Pandas: Provides extended abilities for data cleaning, selection, and feature transformations (DEV Community) (AITechTrend — Further towards the future).

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