Feature Engineering Beats Chasing the Next Algorithm
Summary
The article argues that feature engineering significantly outweighs algorithm selection in improving forecasting model performance. It highlights that machine learning models, which only process numbers, require rich contextual features to recognize meaningful patterns, unlike human analysts who naturally reason with trends and seasonality. While lag features are a starting point, the author emphasizes creating features that describe system behavior, such as four-week growth rates, seasonal baselines, and historical expectation profiles. These features, derived from domain knowledge, provide crucial context that even advanced algorithms like LightGBM, XGBoost, CatBoost, or Transformers cannot inherently discover, ultimately leading to more substantial gains than simply switching models.
Key takeaway
For Data Scientists or Machine Learning Engineers struggling with underperforming forecasting models, prioritize robust feature engineering before exploring new algorithms. Your focus should be on transforming raw data into contextual signals, such as trend indicators, seasonal profiles, and historical expectations, which provide the model with the necessary domain knowledge. This approach often yields greater performance improvements than simply swapping models like LightGBM for Transformers, ensuring your models learn from meaningful patterns.
Key insights
Feature engineering, driven by domain knowledge, provides essential context for forecasting models, surpassing algorithm selection in impact.
Principles
- Models need context, not raw numbers.
- Domain knowledge creates effective features.
- Algorithms can't learn absent information.
Method
Before changing a forecasting algorithm, assess if the model has sufficient context, if behavior is described over raw values, and if domain knowledge is represented as features.
In practice
- Implement trend features like growth rate.
- Use seasonal context (e.g., weeks since season start).
- Create historical expectation profiles.
Topics
- Feature Engineering
- Time Series Forecasting
- Machine Learning Models
- Predictive Analytics
- Domain Knowledge
- Algorithm Selection
Best for: Machine Learning Engineer, Data Scientist, AI Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by Machine Learning on Medium.