20+ Data Scientist Intern Interview Questions and Answers for Freshers

No, compromising project quality is not an option even if the deadline is approaching.

• Quality should never be compromised as it reflects the professionalism and credibility of the work.

• Instead of compromising quality, it is better to communicate with the team and stakeholders to find alternative solutions.

• Prioritize tasks, optimize processes, and work efficiently to meet the deadline without sacrificing quality.

• Seek help or delegate tasks if necessary to ensure both quality a...read more

Implement a function to find the maximum product of two integers in an array.

• Iterate through the array and keep track of the two largest and two smallest integers.

• Calculate the products of the largest and smallest integers and return the maximum product.

Hypothesis testing is a statistical method used to make inferences about a population based on sample data.

• Hypothesis testing involves formulating a null hypothesis and an alternative hypothesis.

• It helps determine if there is enough evidence to reject the null hypothesis in favor of the alternative hypothesis.

• Example: Testing whether a new drug is effective by comparing the recovery rates of a treatment group and a control group.

• Other examples include testing the impact of ad...read more

Identify even/odd numbers, loop through a list, and handle edge cases effectively.

• An even number is divisible by 2 (e.g., 2, 4, 6).

• An odd number is not divisible by 2 (e.g., 1, 3, 5).

• Use the modulus operator (%) to check: number % 2 == 0 for even.

• Loop through a list using a for loop: for number in list.

• Handle edge cases like empty lists or non-integer values.

• Example: For list [1, 2, 3, 4], output would be 'Odd: 1, 3' and 'Even: 2, 4'.

I learn new technologies through online courses, tutorials, hands-on projects, and collaborating with peers.

• Enroll in online courses on platforms like Coursera, Udemy, or edX

• Follow tutorials on websites like Medium, YouTube, or official documentation

• Work on hands-on projects to apply new technologies in real-world scenarios

• Collaborate with peers through hackathons, coding meetups, or online forums

• Stay updated with industry trends by reading blogs, attending webinars, and foll...read more

Factors to consider when cleaning data

• Identifying and handling missing values

• Removing duplicates

• Standardizing data formats

• Handling outliers

• Addressing inconsistencies in data entry

Convolution operation is a mathematical operation that combines two functions to produce a third function.

• Convolution involves sliding one function over another and multiplying the overlapping values at each position.

• It is commonly used in image processing and signal processing to extract features.

• In deep learning, convolutional neural networks use convolution operations to learn spatial hierarchies of features.

Utilize machine learning models to predict employee attrition and take proactive measures to reduce it.

• Collect relevant data such as employee demographics, performance metrics, satisfaction surveys, etc.

• Preprocess the data by handling missing values, encoding categorical variables, and scaling numerical features.

• Split the data into training and testing sets to train the model and evaluate its performance.

• Choose appropriate machine learning algorithms such as logistic regressi...read more

PCA is a dimensionality reduction technique used to transform high-dimensional data into a lower-dimensional space while preserving the most important information.

• PCA helps in identifying patterns in data by reducing the number of variables

• It finds the directions (principal components) along which the variance of the data is maximized

• PCA is commonly used in image processing, genetics, and finance

Random Forest is an ensemble learning algorithm that builds multiple decision trees and combines their predictions.

• Random Forest is a supervised learning algorithm used for classification and regression tasks.

• It creates a forest of decision trees during training, where each tree is built using a random subset of features and data points.

• The final prediction is made by aggregating the predictions of all the individual trees, usually through a majority voting mechanism.

• Random F...read more

Central limit theorem states that the sampling distribution of the sample mean approaches a normal distribution as the sample size increases.

• Central limit theorem is a fundamental concept in statistics.

• It states that the sampling distribution of the sample mean will be approximately normally distributed, regardless of the shape of the population distribution.

• It is important for making inferences about population parameters based on sample data.

• The theorem is used in hypothesi...read more

Pruning is a technique used in machine learning to reduce the size of decision trees by removing unnecessary branches.

• Pruning helps prevent overfitting by simplifying the model

• There are two types of pruning: pre-pruning and post-pruning

• Pre-pruning involves setting a limit on the depth of the tree or the number of leaf nodes

• Post-pruning involves removing branches that do not improve the overall accuracy of the tree

• Example: Removing a branch that only contains data points from ...read more

Use pandas library to read csv files in Python.

• Import pandas library: import pandas as pd

• Use pd.read_csv() function to read csv file

• Specify file path as argument in read_csv() function

• Assign the result to a variable to store the data

• Example: df = pd.read_csv('file.csv')

The assignment output results include data analysis findings and visualizations.

• Generated summary statistics for the dataset

• Created data visualizations using matplotlib or seaborn

• Performed hypothesis testing to draw conclusions

• Used machine learning algorithms for predictive modeling

Proficient in Python with experience in data analysis, machine learning, and automation.

• Used Python for data cleaning, manipulation, and visualization in projects

• Implemented machine learning algorithms using libraries like scikit-learn and TensorFlow

• Automated repetitive tasks using Python scripts and libraries like pandas and NumPy

Machine learning algorithms are methods that enable computers to learn from data and make predictions or decisions.

• Supervised Learning: Algorithms like Linear Regression and Decision Trees use labeled data for training.

• Unsupervised Learning: Techniques such as K-Means Clustering and PCA find patterns in unlabeled data.

• Reinforcement Learning: Algorithms like Q-Learning learn optimal actions through trial and error in an environment.

• Deep Learning: Neural networks, especially Co...read more

Confusion matrix is a table used to evaluate the performance of a classification model.

• It is used to measure the accuracy of a classification model.

• It compares the predicted values with the actual values.

• It consists of four values: true positive, false positive, true negative, and false negative.

• It is commonly used in machine learning and data science.

• It helps in identifying the strengths and weaknesses of a model.

Feature engineering is the process of selecting, modifying, or creating features to improve model performance.

• Identifying relevant features: Selecting variables that have predictive power, e.g., using age and BMI in health-related models.

• Creating new features: Combining existing features, like creating 'total income' from 'monthly salary' and 'annual bonus'.

• Handling missing values: Imputing missing data using mean, median, or mode to maintain dataset integrity.

• Encoding catego...read more

Random Forest is an ensemble learning algorithm used for classification and regression tasks.

• Random Forest builds multiple decision trees and combines their outputs to make a final prediction.

• It is a bagging algorithm that randomly selects a subset of features and data points for each tree.

• Random Forest reduces overfitting and improves accuracy compared to a single decision tree.

• It can handle missing values and outliers in the data.

• Example: Predicting whether a customer will ...read more

Data Science is a field that uses scientific methods, algorithms, and systems to extract knowledge and insights from structured and unstructured data.

• Data Science involves collecting, cleaning, analyzing, and interpreting large amounts of data to make informed decisions.

• It combines statistics, machine learning, data visualization, and domain expertise to solve complex problems.

• Examples include predicting customer behavior based on past purchase data, detecting fraud in financ...read more

The sum of two numbers is the result of adding them together.

• Add the two numbers together to get the sum

• The sum of 5 and 3 is 8 (5 + 3 = 8)

• The sum of -2 and 7 is 5 (-2 + 7 = 5)