Explore Courses
Liverpool Business SchoolLiverpool Business SchoolMBA by Liverpool Business School
  • 18 Months
Bestseller
Golden Gate UniversityGolden Gate UniversityMBA (Master of Business Administration)
  • 15 Months
Popular
O.P.Jindal Global UniversityO.P.Jindal Global UniversityMaster of Business Administration (MBA)
  • 12 Months
New
Birla Institute of Management Technology Birla Institute of Management Technology Post Graduate Diploma in Management (BIMTECH)
  • 24 Months
Liverpool John Moores UniversityLiverpool John Moores UniversityMS in Data Science
  • 18 Months
Popular
IIIT BangaloreIIIT BangalorePost Graduate Programme in Data Science & AI (Executive)
  • 12 Months
Bestseller
Golden Gate UniversityGolden Gate UniversityDBA in Emerging Technologies with concentration in Generative AI
  • 3 Years
upGradupGradData Science Bootcamp with AI
  • 6 Months
New
University of MarylandIIIT BangalorePost Graduate Certificate in Data Science & AI (Executive)
  • 8-8.5 Months
upGradupGradData Science Bootcamp with AI
  • 6 months
Popular
upGrad KnowledgeHutupGrad KnowledgeHutData Engineer Bootcamp
  • Self-Paced
upGradupGradCertificate Course in Business Analytics & Consulting in association with PwC India
  • 06 Months
OP Jindal Global UniversityOP Jindal Global UniversityMaster of Design in User Experience Design
  • 12 Months
Popular
WoolfWoolfMaster of Science in Computer Science
  • 18 Months
New
Jindal Global UniversityJindal Global UniversityMaster of Design in User Experience
  • 12 Months
New
Rushford, GenevaRushford Business SchoolDBA Doctorate in Technology (Computer Science)
  • 36 Months
IIIT BangaloreIIIT BangaloreCloud Computing and DevOps Program (Executive)
  • 8 Months
New
upGrad KnowledgeHutupGrad KnowledgeHutAWS Solutions Architect Certification
  • 32 Hours
upGradupGradFull Stack Software Development Bootcamp
  • 6 Months
Popular
upGradupGradUI/UX Bootcamp
  • 3 Months
upGradupGradCloud Computing Bootcamp
  • 7.5 Months
Golden Gate University Golden Gate University Doctor of Business Administration in Digital Leadership
  • 36 Months
New
Jindal Global UniversityJindal Global UniversityMaster of Design in User Experience
  • 12 Months
New
Golden Gate University Golden Gate University Doctor of Business Administration (DBA)
  • 36 Months
Bestseller
Ecole Supérieure de Gestion et Commerce International ParisEcole Supérieure de Gestion et Commerce International ParisDoctorate of Business Administration (DBA)
  • 36 Months
Rushford, GenevaRushford Business SchoolDoctorate of Business Administration (DBA)
  • 36 Months
KnowledgeHut upGradKnowledgeHut upGradSAFe® 6.0 Certified ScrumMaster (SSM) Training
  • Self-Paced
KnowledgeHut upGradKnowledgeHut upGradPMP® certification
  • Self-Paced
IIM KozhikodeIIM KozhikodeProfessional Certification in HR Management and Analytics
  • 6 Months
Bestseller
Duke CEDuke CEPost Graduate Certificate in Product Management
  • 4-8 Months
Bestseller
upGrad KnowledgeHutupGrad KnowledgeHutLeading SAFe® 6.0 Certification
  • 16 Hours
Popular
upGrad KnowledgeHutupGrad KnowledgeHutCertified ScrumMaster®(CSM) Training
  • 16 Hours
Bestseller
PwCupGrad CampusCertification Program in Financial Modelling & Analysis in association with PwC India
  • 4 Months
upGrad KnowledgeHutupGrad KnowledgeHutSAFe® 6.0 POPM Certification
  • 16 Hours
O.P.Jindal Global UniversityO.P.Jindal Global UniversityMaster of Science in Artificial Intelligence and Data Science
  • 12 Months
Bestseller
Liverpool John Moores University Liverpool John Moores University MS in Machine Learning & AI
  • 18 Months
Popular
Golden Gate UniversityGolden Gate UniversityDBA in Emerging Technologies with concentration in Generative AI
  • 3 Years
IIIT BangaloreIIIT BangaloreExecutive Post Graduate Programme in Machine Learning & AI
  • 13 Months
Bestseller
IIITBIIITBExecutive Program in Generative AI for Leaders
  • 4 Months
upGradupGradAdvanced Certificate Program in GenerativeAI
  • 4 Months
New
IIIT BangaloreIIIT BangalorePost Graduate Certificate in Machine Learning & Deep Learning (Executive)
  • 8 Months
Bestseller
Jindal Global UniversityJindal Global UniversityMaster of Design in User Experience
  • 12 Months
New
Liverpool Business SchoolLiverpool Business SchoolMBA with Marketing Concentration
  • 18 Months
Bestseller
Golden Gate UniversityGolden Gate UniversityMBA with Marketing Concentration
  • 15 Months
Popular
MICAMICAAdvanced Certificate in Digital Marketing and Communication
  • 6 Months
Bestseller
MICAMICAAdvanced Certificate in Brand Communication Management
  • 5 Months
Popular
upGradupGradDigital Marketing Accelerator Program
  • 05 Months
Jindal Global Law SchoolJindal Global Law SchoolLL.M. in Corporate & Financial Law
  • 12 Months
Bestseller
Jindal Global Law SchoolJindal Global Law SchoolLL.M. in AI and Emerging Technologies (Blended Learning Program)
  • 12 Months
Jindal Global Law SchoolJindal Global Law SchoolLL.M. in Intellectual Property & Technology Law
  • 12 Months
Jindal Global Law SchoolJindal Global Law SchoolLL.M. in Dispute Resolution
  • 12 Months
upGradupGradContract Law Certificate Program
  • Self paced
New
ESGCI, ParisESGCI, ParisDoctorate of Business Administration (DBA) from ESGCI, Paris
  • 36 Months
Golden Gate University Golden Gate University Doctor of Business Administration From Golden Gate University, San Francisco
  • 36 Months
Rushford Business SchoolRushford Business SchoolDoctor of Business Administration from Rushford Business School, Switzerland)
  • 36 Months
Edgewood CollegeEdgewood CollegeDoctorate of Business Administration from Edgewood College
  • 24 Months
Golden Gate UniversityGolden Gate UniversityDBA in Emerging Technologies with Concentration in Generative AI
  • 36 Months
Golden Gate University Golden Gate University DBA in Digital Leadership from Golden Gate University, San Francisco
  • 36 Months
Liverpool Business SchoolLiverpool Business SchoolMBA by Liverpool Business School
  • 18 Months
Bestseller
Golden Gate UniversityGolden Gate UniversityMBA (Master of Business Administration)
  • 15 Months
Popular
O.P.Jindal Global UniversityO.P.Jindal Global UniversityMaster of Business Administration (MBA)
  • 12 Months
New
Deakin Business School and Institute of Management Technology, GhaziabadDeakin Business School and IMT, GhaziabadMBA (Master of Business Administration)
  • 12 Months
Liverpool John Moores UniversityLiverpool John Moores UniversityMS in Data Science
  • 18 Months
Bestseller
O.P.Jindal Global UniversityO.P.Jindal Global UniversityMaster of Science in Artificial Intelligence and Data Science
  • 12 Months
Bestseller
IIIT BangaloreIIIT BangalorePost Graduate Programme in Data Science (Executive)
  • 12 Months
Bestseller
O.P.Jindal Global UniversityO.P.Jindal Global UniversityO.P.Jindal Global University
  • 12 Months
WoolfWoolfMaster of Science in Computer Science
  • 18 Months
New
Liverpool John Moores University Liverpool John Moores University MS in Machine Learning & AI
  • 18 Months
Popular
Golden Gate UniversityGolden Gate UniversityDBA in Emerging Technologies with concentration in Generative AI
  • 3 Years
Rushford, GenevaRushford Business SchoolDoctorate of Business Administration (AI/ML)
  • 36 Months
Ecole Supérieure de Gestion et Commerce International ParisEcole Supérieure de Gestion et Commerce International ParisDBA Specialisation in AI & ML
  • 36 Months
Golden Gate University Golden Gate University Doctor of Business Administration (DBA)
  • 36 Months
Bestseller
Ecole Supérieure de Gestion et Commerce International ParisEcole Supérieure de Gestion et Commerce International ParisDoctorate of Business Administration (DBA)
  • 36 Months
Rushford, GenevaRushford Business SchoolDoctorate of Business Administration (DBA)
  • 36 Months
Liverpool Business SchoolLiverpool Business SchoolMBA with Marketing Concentration
  • 18 Months
Bestseller
Golden Gate UniversityGolden Gate UniversityMBA with Marketing Concentration
  • 15 Months
Popular
Jindal Global Law SchoolJindal Global Law SchoolLL.M. in Corporate & Financial Law
  • 12 Months
Bestseller
Jindal Global Law SchoolJindal Global Law SchoolLL.M. in Intellectual Property & Technology Law
  • 12 Months
Jindal Global Law SchoolJindal Global Law SchoolLL.M. in Dispute Resolution
  • 12 Months
IIITBIIITBExecutive Program in Generative AI for Leaders
  • 4 Months
New
IIIT BangaloreIIIT BangaloreExecutive Post Graduate Programme in Machine Learning & AI
  • 13 Months
Bestseller
upGradupGradData Science Bootcamp with AI
  • 6 Months
New
upGradupGradAdvanced Certificate Program in GenerativeAI
  • 4 Months
New
KnowledgeHut upGradKnowledgeHut upGradSAFe® 6.0 Certified ScrumMaster (SSM) Training
  • Self-Paced
upGrad KnowledgeHutupGrad KnowledgeHutCertified ScrumMaster®(CSM) Training
  • 16 Hours
upGrad KnowledgeHutupGrad KnowledgeHutLeading SAFe® 6.0 Certification
  • 16 Hours
KnowledgeHut upGradKnowledgeHut upGradPMP® certification
  • Self-Paced
upGrad KnowledgeHutupGrad KnowledgeHutAWS Solutions Architect Certification
  • 32 Hours
upGrad KnowledgeHutupGrad KnowledgeHutAzure Administrator Certification (AZ-104)
  • 24 Hours
KnowledgeHut upGradKnowledgeHut upGradAWS Cloud Practioner Essentials Certification
  • 1 Week
KnowledgeHut upGradKnowledgeHut upGradAzure Data Engineering Training (DP-203)
  • 1 Week
MICAMICAAdvanced Certificate in Digital Marketing and Communication
  • 6 Months
Bestseller
MICAMICAAdvanced Certificate in Brand Communication Management
  • 5 Months
Popular
IIM KozhikodeIIM KozhikodeProfessional Certification in HR Management and Analytics
  • 6 Months
Bestseller
Duke CEDuke CEPost Graduate Certificate in Product Management
  • 4-8 Months
Bestseller
Loyola Institute of Business Administration (LIBA)Loyola Institute of Business Administration (LIBA)Executive PG Programme in Human Resource Management
  • 11 Months
Popular
Goa Institute of ManagementGoa Institute of ManagementExecutive PG Program in Healthcare Management
  • 11 Months
IMT GhaziabadIMT GhaziabadAdvanced General Management Program
  • 11 Months
Golden Gate UniversityGolden Gate UniversityProfessional Certificate in Global Business Management
  • 6-8 Months
upGradupGradContract Law Certificate Program
  • Self paced
New
IU, GermanyIU, GermanyMaster of Business Administration (90 ECTS)
  • 18 Months
Bestseller
IU, GermanyIU, GermanyMaster in International Management (120 ECTS)
  • 24 Months
Popular
IU, GermanyIU, GermanyB.Sc. Computer Science (180 ECTS)
  • 36 Months
Clark UniversityClark UniversityMaster of Business Administration
  • 23 Months
New
Golden Gate UniversityGolden Gate UniversityMaster of Business Administration
  • 20 Months
Clark University, USClark University, USMS in Project Management
  • 20 Months
New
Edgewood CollegeEdgewood CollegeMaster of Business Administration
  • 23 Months
The American Business SchoolThe American Business SchoolMBA with specialization
  • 23 Months
New
Aivancity ParisAivancity ParisMSc Artificial Intelligence Engineering
  • 24 Months
Aivancity ParisAivancity ParisMSc Data Engineering
  • 24 Months
The American Business SchoolThe American Business SchoolMBA with specialization
  • 23 Months
New
Aivancity ParisAivancity ParisMSc Artificial Intelligence Engineering
  • 24 Months
Aivancity ParisAivancity ParisMSc Data Engineering
  • 24 Months
upGradupGradData Science Bootcamp with AI
  • 6 Months
Popular
upGrad KnowledgeHutupGrad KnowledgeHutData Engineer Bootcamp
  • Self-Paced
upGradupGradFull Stack Software Development Bootcamp
  • 6 Months
Bestseller
KnowledgeHut upGradKnowledgeHut upGradBackend Development Bootcamp
  • Self-Paced
upGradupGradUI/UX Bootcamp
  • 3 Months
upGradupGradCloud Computing Bootcamp
  • 7.5 Months
PwCupGrad CampusCertification Program in Financial Modelling & Analysis in association with PwC India
  • 5 Months
upGrad KnowledgeHutupGrad KnowledgeHutSAFe® 6.0 POPM Certification
  • 16 Hours
upGradupGradDigital Marketing Accelerator Program
  • 05 Months
upGradupGradAdvanced Certificate Program in GenerativeAI
  • 4 Months
New
upGradupGradData Science Bootcamp with AI
  • 6 Months
Popular
upGradupGradFull Stack Software Development Bootcamp
  • 6 Months
Bestseller
upGradupGradUI/UX Bootcamp
  • 3 Months
PwCupGrad CampusCertification Program in Financial Modelling & Analysis in association with PwC India
  • 4 Months
upGradupGradCertificate Course in Business Analytics & Consulting in association with PwC India
  • 06 Months
upGradupGradDigital Marketing Accelerator Program
  • 05 Months

Decision Tree Classification: Everything You Need to Know

Updated on 24 November, 2022

6.52K+ views
7 min read

Introduction

Many analogies could be driven from nature into our real lives; trees happen to be one of the most influential of them. Trees have made their impact on a considerable area of machine learning. They cover both the essential classification and regression. When analyzing any decision, a decision tree classifier could be employed to represent the process of decision making.

So, basically, a decision tree happens to be a part of supervised machine learning where the processing of data happens by splitting the data continuously, all the while keeping in mind a particular parameter.

What are decision trees made of?

The answer to the question is straightforward. Decision trees are made of three essential things, the analogy to each one of them could be drawn to a real-life tree. All three of them are listed below:

  1. Nodes: This is the place where the testing for the value happens. In a node, the value of a specific attribute is passed, and it’s checked and tested against the values to make a decision.  
  2. Edges/Branches: This portion corresponds to the outcome of any test result. Edges/Branches are also responsible for linking two different nodes or leaves.
  3. Leaf Nodes: These are the nodes that are typically found at the terminals. Leaf nodes are responsible for predicting the outcome.

Get Machine Learning Certification from the World’s top Universities. Earn Masters, Executive PGP, or Advanced Certificate Programs to fast-track your career.

Decision tree classification

The decision trees can be broadly classified into two categories, namely, Classification trees and Regression trees.

1. Classification trees

Classification trees are those types of decision trees which are based on answering the “Yes” or “No” questions and using this information to come to a decision. So, a tree, which determines whether a person is fit or unfit by asking a bunch of related questions and using the answers to come to a viable solution, is a type of classification tree.

These types of trees are usually constructed by employing a process which is called binary recursive partitioning. The method of binary recursive partitioning involves splitting the data into separate modules or partitions, and then these partitions are further spliced into every branch of the decision tree classifier.

2. Regression Trees

Now, a regression type of decision tree is different from the classification type of decision tree in one aspect. The data that has been fed into the two trees are very different. The classification trees handle the data, which is discreet, while the regression decision trees handle the continuous data type. A good example of regression trees would be the house price or how long a patient will typically stay in the hospital.

Learn more: Linear Regression in Machine Learning

How are the decision trees created?

Decision trees are created by taking the set of data that the model has to be trained on (decision trees are a part of supervised machine learning). This training dataset is to be continuously spliced into smaller data subsets. This process is complemented by the creation of an association tree that incrementally gets created side by side in the process of breaking down the data. After the machine has finished learning, the creation of a decision tree based on the training dataset that has been provided concludes, and this tree is then returned to the user.

The central idea behind using a decision tree is to separate the data into two primary regions, the region with the dense population (cluster) or the area, which are empty (or sparse) regions.

Decision Tree classification works on an elementary principle of the divide. It conquers where any new example which has been fed into the tree, after going through a series of tests, would be organized and given a class label. The algorithm of divide and conquer is discussed in details below:

Divide and conquer

It is apparent that the decision tree classifier is based and built by making use of a heuristic known as recursive partitioning, also known as the divide and conquer algorithm. It breaks down the data into smaller sets and continues to do so. Until it has determined that the data within each subset is homogenous, or if the user has defined another stopping criterion, that would put a stop to this algorithm.

How does the decision tree classifier work?

  1. The divide and conquer algorithm is used to create a decision tree classifier. By making the use of the algorithm we always begin at the root of the tree and we also split the dataset to reduce the uncertainty in the final decision.
  2. It happens to be an iterative process. So, we repeat this process at every node. This process is repeated until the time we don’t have the nodes of the purity we desire.
  3. Generally, to avoid overfitting we set a limit of purity to be achieved. This means the final result might not be 100% pure.

Basics of the divide and conquer algorithm:

  1. First comes choosing or selecting a test for the root node. Then begins the process of creating branches. The branches are designed with keeping in mind each possible outcome of the trial that has been defined.
  2. Next comes the splitting of the instances of data into smaller subsets. Each branch would have its own splice, which is connected to the node.
  3. This process then has to be repeated for each branch by using just the instances which come to the branch in question.
  4. This recursive process should be stopped if all the instances belong to the same class.

Advantages of using decision tree classification

  1. It does not require a tremendous amount of money to construct.
  2. It is a swift process of classification of records that are new or unknown.
  3. It can be very easily interpreted, especially if the tree is small in size.
  4. The accuracy of prediction using the decision tree classifier is comparable to other methods of prediction or classification.
  5. It also has the capability to exclude the features which are unimportant. This process of eliminating irrelevant features is done automatically.

Read: How to create perfect decision tree?

Disadvantages of using the decision tree classifier

  1. Overfitting the dataset is very easy in this case.
  2. The boundary of the decision has a restriction. It can only be parallel to the axes, which contains the attributes.
  3. Models based on decision trees often have biased-on splits that have a massive number of levels.
  4. Any small changes made on the dataset can have a significant impact on the logic which governs the decision.
  5. Lager trees are challenging to understand because sometimes they might feel very counter-intuitive.

Also read: Decision Trees in Machine Learning

Learn data science courses from the World’s top Universities. Earn Executive PG Programs, Advanced Certificate Programs, or Masters Programs to fast-track your career.

Conclusion

Decision trees come in handy while we are faced with problems that cannot be handled with linear solutions. From observations, it has been noted that tree-based models can easily map the non-linearity of the inputs and effectively eliminate the problem at hand. Sophisticated methods like random forest generation and gradient boosting are all based on the decision tree classifier itself.

Decision trees are a potent tool which can be used in many areas of real life such as, Biomedical Engineering, astronomy, system control, medicines, physics, etc. This effectively makes decision tree classification a critical and indispensable tool of machine learning.

Frequently Asked Questions (FAQs)

1. Are Decision Trees inclined to overfit?

Decision Trees fragment the complex data into simpler forms. A Decision Tree classification tries to divide data until it can’t be further divided. A clear chart of all the possible contents is then created, which helps in further analysis. While a vast tree with numerous splices gives us a straight path, it can also generate a problem when testing the data. This excessive splicing leads to overfitting, wherein many divisions cause the tree to grow tremendously. In such cases, the predictive ability of the Decision Tree is compromised, and hence it becomes unsound. Pruning is a technique used to deal with overfitting, where the excessive subsets are removed.

2. Do Decision Trees need normalisation?

Decision Trees are the most common machine learning algorithm used for the classification and regression of data. This supervised mechanism splices data per subset into various groups until it reaches the leaf node, where it cannot be divided further. Since this data will be split into categories based on the provided attributes, it will be evenly split. It conveys that both data that went through normalisation and data that didn’t would have the same number of splits. Therefore, normalisation is not a prerequisite for decision-based tree models.

3. How to splice Decision Trees?

Decision Trees are a reliable mechanism to classify data and predict solutions. Splicing in a Decision Tree requires precision; one slight mistake can compromise the Decision Tree’s integrity. Splicing in a Decision Tree occurs using recursive partitioning. Splitting data starts with making subsets of data through the attributes assigned to it. The data is split recursively in repetition until the spliced data at each node is deemed obsolete in predicting solutions. The subset can be similar to the value of the target variable as well. Splicing has to be methodical and repetitive for good accuracy.