Here are 15 interview questions related to LightGBM, a gradient-boosting framework developed by Microsoft, along with their answers:
1. What is LightGBM?
Ans: LightGBM is an open-source gradient-boosting framework developed by Microsoft. It is designed to be efficient, and scalable, and provide high-performance machine learning algorithms for both classification and regression tasks.
2. What are the key features of LightGBM?
Ans: The key features of LightGBM include its ability to handle large-scale datasets, efficient training speed, support for categorical features, advanced tree-based algorithms, and customizable hyperparameters.
3. How does LightGBM differ from other gradient-boosting frameworks?
Ans: LightGBM differs from other gradient-boosting frameworks in its focus on efficiency and scalability. It uses a novel technique called Gradient-based One-Side Sampling (GOSS) to select and process training instances efficiently.
4. What is the advantage of using LightGBM for large-scale datasets?
Ans: LightGBM is designed to handle large-scale datasets efficiently by utilizing a histogram-based algorithm and data parallelism. It reduces memory usage and training time, making it suitable for big data applications.
5. How does LightGBM handle categorical features?
Ans: LightGBM supports handling categorical features directly, without the need for one-hot encoding. It uses a technique called “split finding” to build the trees, which can directly handle categorical data.
6. Can LightGBM handle missing values in the dataset?
Ans: Yes, LightGBM can handle missing values in the dataset. It has built-in support for handling missing values during the training process.
7. Does LightGBM support parallel and distributed computing?
Ans: Yes, LightGBM supports parallel and distributed computing. It can utilize multiple CPU cores and can be run in distributed computing environments such as Hadoop and Spark.
8. What are the different boosting algorithms available in LightGBM?
Ans: LightGBM supports several boosting algorithms, including Gradient Boosting Decision Tree (GBDT), Random Forest, and Gradient-based One-Side Sampling (GOSS).
9. How does LightGBM handle overfitting?
Ans: LightGBM provides multiple mechanisms to handle overfitting, such as regularization techniques (e.g., L1 and L2 regularization), early stopping, and controlling the maximum depth of trees.
10. Can LightGBM handle imbalanced datasets?
Ans: Yes, LightGBM provides options to handle imbalanced datasets. It supports class weights, which can be used to give more importance to minority classes and evaluation metrics specifically designed for imbalanced classification tasks, such as AUC-PR.
11. What evaluation metrics are available in LightGBM?
Ans: LightGBM provides a variety of evaluation metrics for classification and regression tasks, including accuracy, log loss, AUC, RMSE, and many others. It also supports custom evaluation metrics.
12. How can you handle feature scaling in LightGBM?
Ans: LightGBM does not require explicit feature scaling. It uses a gradient-based algorithm that is not affected by the scale of features.
13. Can LightGBM handle large categorical features with high cardinality?
Ans: Yes, LightGBM can handle large categorical features with high cardinality efficiently. It uses a technique called “Gradient-based One-Hot Encoding” to encode categorical features, which reduces memory usage and computational cost.
14. Does LightGBM support cross-validation?
Ans: Yes, LightGBM supports cross-validation. It provides functionality for performing k-fold cross-validation to estimate the model’s performance on unseen data.
15. Can you save and load LightGBM models?
Ans: Yes, LightGBM allows users to save trained models to disk and load them later for inference or further training. The models can be saved in binary format or as a JSON file.