NielsenIQ Data Scientist Interview Questions and Answers

I chose Data Science field because of its potential to solve complex problems and make a positive impact on society.

• Fascination with data and its potential to drive insights

• Desire to solve complex problems and make a positive impact on society

• Opportunity to work with cutting-edge technology and tools

• Ability to work in a variety of industries and domains

• Examples: Predictive maintenance in manufacturing, fraud detection

Linear Regression is used for predicting continuous numerical values, while Logistic Regression is used for predicting binary categorical values.

• Linear Regression predicts a continuous output, while Logistic Regression predicts a binary output.

• Linear Regression uses a linear equation to model the relationship between the independent and dependent variables, while Logistic Regression uses a logistic function.

• Linear Regr...read more

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

• It is a 2x2 matrix that shows the number of true positives, false positives, true negatives, and false negatives.

• It helps in calculating various metrics like accuracy, precision, recall, and F1 score.

• It is useful in identifying the strengths and weaknesses of a model and improving its performance.

• Example: In a binary classification p...read more

No, confusion matrix is not used in Linear Regression.

• Confusion matrix is used to evaluate classification models.

• Linear Regression is a regression model, not a classification model.

• Evaluation metrics for Linear Regression include R-squared, Mean Squared Error, etc.

KNN is a non-parametric algorithm used for classification and regression tasks.

• KNN stands for K-Nearest Neighbors.

• It works by finding the K closest data points to a given test point.

• The class or value of the test point is then determined by the majority class or average value of the K neighbors.

• KNN can be used for both classification and regression tasks.

• It is a simple and easy-to-understand algorithm, but can be compu

Random Forest is an ensemble learning method that builds multiple decision trees and combines their outputs to improve accuracy.

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

• It creates multiple decision trees and combines their outputs to make a final prediction.

• Each decision tree is built using a random subset of features and data points to reduce overfitting.

• Ran...read more

I have worked on various projects involving data analysis, machine learning, and predictive modeling.

• Developed a predictive model to forecast customer churn for a telecommunications company.

• Built a recommendation system using collaborative filtering for an e-commerce platform.

• Performed sentiment analysis on social media data to understand customer opinions and preferences.

• Implemented a fraud detection system using anom...read more