Contents

- 1 Is a decision tree a binary tree?
- 2 Can decision trees be non binary?
- 3 Can decision trees be used for binary classification tasks?
- 4 How will you counter overfitting in the decision tree?
- 5 What is the difference between decision tree and random forest?
- 6 How many types of decision trees are possible?
- 7 How many nodes are there in a decision tree?
- 8 How do you determine the best split in decision tree?
- 9 Can decision trees only predict discrete outcomes?
- 10 What are the disadvantages of decision trees?
- 11 Which algorithm is best for multiclass classification?
- 12 What is a classification algorithm?
- 13 What are decision tree models?

## Is a decision tree a binary tree?

A Binary Decision Tree is a structure based on a sequential decision process. Starting from the root, a feature is evaluated and one of the two branches is selected. This procedure is repeated until a final leaf is reached, which normally represents the classification target you’re looking for.

## Can decision trees be non binary?

CHAID builds non-binary trees (i.e., trees where more than two branches can attach to a single root or node). Both CHAID and CART will construct trees, where each (non-terminal) node identifies a split condition. Hence, both types of algorithms can be applied to analyze regression problems or classification.

## Can decision trees be used for binary classification tasks?

Can decision tree be used for classification tasks?(single option) a) yes but only for binary classification tasks.

## How will you counter overfitting in the decision tree?

increased test set error. There are several approaches to avoiding overfitting in building decision trees. Pre-pruning that stop growing the tree earlier, before it perfectly classifies the training set. Post-pruning that allows the tree to perfectly classify the training set, and then post prune the tree.

## What is the difference between decision tree and random forest?

A decision tree combines some decisions, whereas a random forest combines several decision trees. Thus, it is a long process, yet slow. Whereas, a decision tree is fast and operates easily on large data sets, especially the linear one. The random forest model needs rigorous training.

## How many types of decision trees are possible?

There are two main types of decision trees that are based on the target variable, i.e., categorical variable decision trees and continuous variable decision trees.

## How many nodes are there in a decision tree?

A decision tree typically starts with a single node, which branches into possible outcomes. Each of those outcomes leads to additional nodes, which branch off into other possibilities. This gives it a treelike shape. There are three different types of nodes: chance nodes, decision nodes, and end nodes.

## How do you determine the best split in decision tree?

Decision Tree Splitting Method #1: Reduction in Variance

- For each split, individually calculate the variance of each child node.
- Calculate the variance of each split as the weighted average variance of child nodes.
- Select the split with the lowest variance.
- Perform steps 1-3 until completely homogeneous nodes are achieved.

## Can decision trees only predict discrete outcomes?

Decision trees belong to a class of supervised machine learning algorithms, which are used in both classification (predicts discrete outcome) and regression (predicts continuous numeric outcomes) predictive modeling.

## What are the disadvantages of decision trees?

Disadvantages of decision trees: They are unstable, meaning that a small change in the data can lead to a large change in the structure of the optimal decision tree. They are often relatively inaccurate. Many other predictors perform better with similar data.

## Which algorithm is best for multiclass classification?

Popular algorithms that can be used for multi-class classification include:

- k-Nearest Neighbors.
- Decision Trees.
- Naive Bayes.
- Random Forest.
- Gradient Boosting.

## What is a classification algorithm?

A classification algorithm, in general, is a function that weighs the input features so that the output separates one class into positive values and the other into negative values. It is generated by plotting the sensitivity versus specificity, as the threshold of the distance from classifier boundary is changed.

## What are decision tree models?

Decision Trees (DTs) are a non-parametric supervised learning method used for classification and regression. The goal is to create a model that predicts the value of a target variable by learning simple decision rules inferred from the data features. A tree can be seen as a piecewise constant approximation.