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Machine Learning Interview Questions in 2022

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Businesses are attempting to make information and services more accessible to individuals by implementing cutting-edge technology such as artificial intelligence (AI) and machine learning. These technologies are becoming more prevalent in industries such as banking, finance, retail, manufacturing, healthcare, and others. So before giving an interview you need to know what questions will be asked in Machine Learning

Some of the in-demand organizational roles that are embracing AI are data scientists, artificial intelligence engineers, machine learning engineers, and data analysts. If you want to apply for these jobs, you need to be aware of the types of machine learning interview questions that recruiters and hiring managers may ask.

Machine Learning

This post will walk you through some of the machine learning interview questions and answers you may encounter on your road to landing your dream job.

Top Machine Learning

Interview Questions

Let’s begin with some of the most often asked machine learning interview questions and answers.

1. Why is the Machine Learning trend evolving rapidly?

Machine Learning solves real-world problems. Its algorithms, as opposed to hard-coding rules to solve problems, learn from data.

The feature can be forcast with the help of learned information. Early adopters are reaping the benefits.

A whopping 82% of businesses that have implemented machine learning and artificial intelligence (AI) have seen a significant financial return on their investments.

Companies have an amazing median ROI of 17%, according to Deloitte.

2. Why was Machine Learning Introduced?

The most straightforward answer is to make our lives easier. Many systems employed hardcoded rules of “if” and “else” decisions to process data or change user input in the early days of “intelligent” applications. Consider a spam filter, whose job it is to shift relevant incoming email messages to a spam folder.

However, using machine learning algorithms, we provide adequate information for the data to learn and find patterns.

Unlike with traditional problems, we do not need to define new rules for each problem in machine learning; instead, we just apply the same methodology but with a different dataset.

Let’s start with Alan Turing. In his 1950 work “Computing Machinery and Intelligence,” Alan posed the question, “Can machines think?”

3. What are the Different Types of Machine Learning algorithms?

There are various types of machine learning algorithms.

Here is a collection of them organized by general category:

Machine Learning Types
  • They trained with human supervision (Supervised, unsupervised, reinforcement learning)
  • The criteria in the figure below are not mutually exclusive; we may combine them in any way we see fit.

4. What is Overfitting, and How Can You Avoid It? 

Overfitting happens when a model learns the training set too well, interpreting random oscillations in the training data as concepts. These have an influence on the model’s capacity to generalize and are not applicable to fresh data.

When given training data, a model achieves 100 percent accuracy—technically a tiny loss. However, there may be inaccuracy and low efficiency when we use the test data. They areto as overfitting.

There are several methods for preventing overfitting, including:

  • Regularization. It includes a cost word for the characteristics associated with the objective function.
  • Regularization. It involves a cost term for the features involved with the objective function
  • Making a simple model.
  • You may also utilize cross-validation techniques like k-folds.
  • Regularisation techniques such as LASSO can be used to penalize model parameters that are likely to lead to overfitting.

5. What are the ‘training Set’ and ‘test Set’ in a Machine Learning Model? How Much Data Will You Allocate for Your Training, Validation, and Test Sets?

To construct a model, a three-step approach is used:

  • Build the model
  • Test out the model.
  • Deploy the model.
Training SetTest Set
The training set contains instances for the model to study and learn from.The test set is used to evaluate the model’s hypothesis generation accuracy.
Typically, 70% of the entire data is used as the training dataset.The remaining 30% is used as a testing dataset.
This is labeled data that will be used to train the model.We run tests without labeled data and then confirm the results using labels.

Consider the following scenario: you have labeled data for 1,000 records. Exposing all 1,000 records during the training phase is one method for training the model. Then you take a small set of the same data to test the model, which would give good results in this case.

Train data set

However, this is not an accurate method of testing.So, we set aside a portion of that data called the ‘test set’ before starting the training process.  The remaining data is called the ‘training set’ which is used for training the model.  The training data is fed into the model several times until the accuracy is high and the mistakes are minimal.

We now run the test data to see if the model can reliably predict the values and if the training is effective. If you encounter problems, you must either alter your model or retrain it with additional data.

test data set

There is no standard rule for dividing data into a training set and a test set, and the ratio might vary depending on individual preferences.

6. How Do You Handle Missing or Corrupted Data in a Dataset?

Dropping certain rows or columns or replacing them totally with another value is one of the simplest methods to deal with missing or erroneous data.

Pandas provide two helpful methods:

  • IsNull() and dropna() will assist in locating and dropping missing data columns/rows.
  • Fillna() will substitute a placeholder value for any incorrect values.
Machine Learning Algorithm corrupted data

7. How Can You Choose a Classifier Based on a Training Set Data Size?

When the training set is tiny, a model with a right bias and low variance appears to perform better because it is less prone to overfitting.

For example, when the training set is huge, Naive Bayes performs well. Models with low bias and large variance perform better because they can handle complicated relationships.

8. What Is a False Positive and False Negative and How Are They Significant?

False positives are those cases that wrongly get classified as True but are False. 

False negatives are those cases that wrongly get classified as False but are True.

The word ‘Positive’ in the phrase ‘False Positive’ refers to the ‘Yes’ row of the expected value in the confusion matrix. The full word shows that the system anticipated a positive result, while the actual value is negative.

Machine Learning Confusion Matrix

So, looking at the confusion matrix, we get:

False-positive = 8

True positive = 14

Similarly, in the term ‘False Negative,’ the word ‘Negative’ refers to the ‘No’ row of the predicted value in the confusion matrix. And the complete term indicates that the system has predicted it as negative, but the actual value is positive.

So, looking at the confusion matrix, we get:

False Negative = 2

True Negative = 10

9. What Are the Three Stages of Building a Model in Machine Learning?

The three steps of developing a machine learning model are as follows:

  • Model Construction

Select an appropriate algorithm for the model and train it in accordance with the specifications.

  • Model Validation

Examine the model’s accuracy using the test data.

  • Using the Model

After testing, make the necessary modifications and utilize the final model for real-time applications.

It is crucial to remember that the model has to be regularly checked to make sure it is operating effectively. To make sure it’s up to date, it should be updated.

10. What is Deep Learning?

Deep learning is a branch of machine learning that uses artificial neural networks to create systems that think and learn like people. The word “deep” refers to the fact that neural networks can contain several layers.

One significant difference between machine learning and deep learning is that feature engineering in machine learning is done manually. In the case of deep learning, the neural network model will automatically choose which features to employ (and which not to use).

11. What Are the Differences Between Machine Learning and Deep Learning?

Machine LearningDeep Learning
Allows robots to make judgments on their own using historical data.Allows robots to make judgments using artificial neural networks.
It simply requires a tiny quantity of data to train.A vast amount of training data is required.
It works well on low-end systems, thus huge computers are not required.It necessitates high-end equipment because of the large amount of computational power required.
The majority of features must be identified in advance and manually programmed.The computer learns the characteristics from the data presented to it.

12. What is Supervised Learning?

Supervised learning refers to a machine learning algorithm for inferring a function from labeled training data. A series of training examples constitute the training data.


Knowing the person’s height and weight allows you to determine their gender. Below is a list of supervised learning algorithms.

Regression Using Support Vector Machines
Naive Bayes Decision Trees, the K-nearest Neighbor Algorithm, and Neural Networks are all examples of decision trees.

13. What is Unsupervised Learning?

Unsupervised learning is a technique for detecting patterns in a set of data. There is no dependent variable or label to forecast in this case. Unsupervised Learning Algorithms:

Some of the techniques used include clustering, anomaly detection, neural networks, and latent variable models.

14. What is Semi-supervised Machine Learning?

Supervised learning makes use of fully labeled data, whereas unsupervised learning makes no use of any training data.

Semi supervised Learning

The training data in semi-supervised learning comprises a small quantity of labeled data and a big amount of unlabeled data.

15. What Are Unsupervised Machine Learning Techniques?

Unsupervised Learning has two techniques they are:-Clustering & Association



Clustering challenges need the division of data into subgroups. These subsets, often known as clusters, include data that is comparable to one another. Unlike classification or regression, distinct clusters provide different characteristics of the objects.


Association ML Algo

We find patterns of relationships between distinct variables or objects in an association issue.

For example, an e-commerce website can recommend other things to you based on previous purchases, spending patterns, items on your wishlist, other customers’ buying behaviors, and so on.

16. What is the Difference Between Supervised and Unsupervised Machine Learning?

Supervised learning – This model learns from labeled data and predicts the future as an output.
Unsupervised learning – These models use unlabeled input data and allow the algorithm to operate on it without supervision.

17. Compare K-means and KNN Algorithms

K-Means is unsupervisedKNN is supervised in nature
A clustering algorithm is K-Means.KNN is a classification algorithm
The points in each cluster are similar to one another, yet they are distinct from the clusters around them.It classifies an unlabeled observation based on its K (can be any number) surrounding neighbors

18. What Is ‘naive’ in the Naive Bayes Classifier?

Because it makes assumptions that may or may not be true, the classifier is referred to as “naive.”

Given the class variable, the method assumes that the existence of any one characteristic of a class has no bearing on the presence of any other feature (absolute independence of features).

For instance, regardless of other characteristics, a fruit may be regarded as a cherry if it is red in colour and spherical in shape. This presumption could or might not be accurate (as an apple also matches the description).

19. What are Support Vectors in SVM?

Support vectors In SVM

A Support Vector Machine (SVM) algorithm seeks to fit a line (or plane or hyperplane) that minimizes the distance from the line to the points of the classes while maximizing the distance from the line to the line.

It seeks to establish a strong division between the classes in this manner. As seen in the picture below, the Support Vectors are the locations along the dividing hyperplane’s edge.

20. Explain the Difference Between Classification and Regression?

Classification Regression
Classification is used to produce discrete results, classification is used to classify data into some specific categories.Whereas, regression deals with continuous data.
Classification is used to predict the output of a group of classes. Whereas, regression is used to predict the relationship that data represents
For example, classifying emails into spam and non-spam categoriesFor example, predicting stock prices at a certain point in time.


The fundamentals of machine learning are the questions listed above which can be asked in an interview. Since machine learning is developing so quickly, new ideas will arise. So to stay updated with these emerging technologies join communities, go to conferences, and read research papers. By doing so you can crack any questions in a Machine learning interview. Comment below which question and the answer did you like the most and don’t forget to stay updated with us on the forum.

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