Data Science & Machine Learning

What are the benefits of a single decision tree compared to more complex models? easy to implement fast training fast inference good explainability

What are the decision trees? This is a type of supervised learning algorithm that is mostly used for classification problems. Surprisingly, it works for both categorical and continuous dependent variables. In this algorithm, we split the population into two or more homogeneous sets. This is done based on most significant attributes/ independent variables to make as distinct groups as possible. A decision tree is a flowchart-like tree structure, where each internal node (non-leaf node) denotes a test on an attribute, each branch represents an outcome of the test, and each leaf node (or terminal node) holds a value for the target variable. Various techniques : like Gini, Information Gain, Chi-square, entropy.

What is feature selection? Why do we need it? Feature Selection is a method used to select the relevant features for the model to train on. We need feature selection to remove the irrelevant features which leads the model to under-perform.

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Understanding Python's Slice Function

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What do we do with categorical variables? Categorical variables must be encoded before they can be used as features to train a machine learning model. There are various encoding techniques, including: One-hot encoding Label encoding Ordinal encoding Target encoding

What is the area under the PR curve? Is it a useful metric? The Precision-Recall AUC is just like the ROC AUC, in that it summarizes the curve with a range of threshold values as a single score. A high area under the curve represents both high recall and high precision, where high precision relates to a low false positive rate, and high recall relates to a low false negative rate.