Data Science Interview Questions for Beginners - Set 1

Explore foundational concepts in data science with this beginner-friendly set of interview questions. Whether you’re gearing up for interviews or just starting to explore data science, these questions will enhance your understanding of important concepts and techniques in the field.

Data Science Interview Questions for Beginners – Set 1

Question 1: Which data structure is used to store unique elements in Python?

List
Tuple
Dictionary
Set

View Answer

Answer: Set

Question 2: Which Python library is commonly used for numerical computing?

NumPy
pandas
TensorFlow
SciPy

View Answer

Answer: NumPy

Question 3: In a normal distribution, what percentage of data falls within one standard deviation from the mean?

99.7%
95%
50%
68%

View Answer

Answer: 68%

Question 4: What is the purpose of cross-validation in machine learning?

To evaluate model performance on unseen data
To increase training time
To reduce bias in the model
To overfit the model

View Answer

Answer: To evaluate model performance on unseen data

Question 5: Which of the following is not a data visualization tool?

Jupyter Notebook
Tableau
matplotlib
Power BI

View Answer

Answer: Jupyter Notebook

Question 6: What is the formula for calculating correlation coefficient?

Variance(X) * Variance(Y) / Covariance(X,Y)
Covariance(X,Y) / (Variance(X) * Variance(Y))
Standard Deviation(X) * Standard Deviation(Y) / Covariance(X,Y)
Covariance(X,Y) / (Standard Deviation(X) * Standard Deviation(Y))

View Answer

Answer: Covariance(X,Y) / (Standard Deviation(X) * Standard Deviation(Y))

Question 7: Which of the following is a supervised learning algorithm?

Decision tree
K-means clustering
K-nearest neighbors
Apriori algorithm

View Answer

Answer: Decision tree

Question 8: What is the purpose of regularization in machine learning?

To increase model complexity
To increase bias and reduce variance
To speed up training time
To reduce overfitting

View Answer

Answer: To reduce overfitting

Question 9: Which of the following is not a type of data distribution?

Poisson distribution
Binomial distribution
Normal distribution
Sequential distribution

View Answer

Answer: Sequential distribution

Question 10: Which of the following is not a type of data distribution skewness?

Infinite skewness
Zero skewness
Negative skewness
Positive skewness

View Answer

Answer: Infinite skewness

Question 11: What is the purpose of a boxplot?

To compare multiple datasets
To display the relationship between two variables
To display the distribution of a dataset
To identify outliers in a dataset

View Answer

Answer: To identify outliers in a dataset

Question 12: Which of the following is not a step in the CRISP-DM (Cross-Industry Standard Process for Data Mining) framework?

Modeling
Deployment
Data Visualization
Evaluation

View Answer

Answer: Data Visualization

Question 13: What is the p-value in hypothesis testing?

Probability of rejecting a false null hypothesis
Probability of rejecting a true null hypothesis
Probability of accepting a true null hypothesis
Probability of accepting a false null hypothesis

View Answer

Answer: Probability of accepting a false null hypothesis

Question 14: Which of the following is not a dimensionality reduction technique?

Singular Value Decomposition
t-Distributed Stochastic Neighbor Embedding (t-SNE)
Linear Regression
Principal Component Analysis (PCA)

View Answer

Answer: Linear Regression

Question 15: Which of the following is not a type of join in SQL?

Outer join
Parallel join
Cross join
Inner join

View Answer

Answer: Parallel join

Question 16: What does SQL stand for?

Standard Query Language
Sequential Query Language
Structured Question Language
Structured Query Language

View Answer

Answer: Structured Query Language

Question 17: Which algorithm is used for outlier detection?

Decision tree
Linear Regression
Isolation Forest
K-means clustering

View Answer

Answer: Isolation Forest

Question 18: Which of the following is used to detect and handle missing values in a dataset?

Mean imputation
All of the above
Median imputation
Mode imputation

View Answer

Answer: All of the above

Question 19: Which Python library is commonly used for web scraping?

BeautifulSoup
pandas
NumPy
SciPy

View Answer

Answer: BeautifulSoup

Question 20: Which of the following is a supervised learning algorithm used for classification?

PCA (Principal Component Analysis)
Decision tree
K-means clustering
t-SNE (t-Distributed Stochastic Neighbor Embedding)

View Answer

Answer: Decision tree

Question 21: Which of the following is not a type of SQL constraint?

Foreign Key
Primary Key
Secondary Key
Unique

View Answer

Answer: Secondary Key

Question 22: What is the primary purpose of ETL (Extract, Transform, Load) in data warehousing?

To prepare data for analysis
To store data
To analyze data
To visualize data

View Answer

Answer: To prepare data for analysis

Question 23: What is the purpose of feature scaling in machine learning?

To reduce the number of features
To increase the dimensionality of the dataset
To introduce noise into the dataset
To standardize the range of independent variables

View Answer

Answer: To standardize the range of independent variables

Question 24: Which statistical measure is used to measure the central tendency of a dataset?

Variance
Standard Deviation
Correlation
Mean

View Answer

Answer: Mean

Question 25: Which of the following is used to represent missing or null values in pandas?

NaN
None
NA
All of the above

View Answer

Answer: NaN