Data Science Interview Questions and Answers for Freshers

Python is a versatile programming language known for its simplicity, readability, and extensive libraries for data science.

• Easy to Learn: Python's syntax is clear and intuitive, making it accessible for beginners and experienced programmers alike.

• Extensive Libraries: Python has a rich ecosystem of libraries like NumPy, Pandas, and Matplotlib for data manipulation and analysis.

• Cross-Platform: Python runs on various operating systems, including Windows, macOS, and Linux, ensuri...read more

The Central Limit Theorem states that the distribution of sample means approaches normality as sample size increases.

• Central Limit Theorem (CLT): Regardless of the population distribution, the sampling distribution of the mean will be approximately normal if the sample size is large enough (n > 30).

• P-Value: The p-value measures the strength of evidence against the null hypothesis; a low p-value (typically < 0.05) indicates strong evidence to reject the null hypothesis.

• Type I ...read more

Troubleshooting model accuracy involves systematic checks, while imbalanced data requires specific techniques to address bias.

• Monitor Data Drift: Check if the input data distribution has changed since the model was trained, which can affect accuracy.

• Evaluate Model Performance: Use metrics like precision, recall, and F1-score to get a better understanding of model performance beyond accuracy.

• Feature Importance Analysis: Identify if certain features have become less relevant or...read more

List and tuple are both data structures in Python used to store collections of items.

• Lists are mutable, meaning their values can be changed after creation.

• Tuples are immutable, meaning their values cannot be changed after creation.

• Lists are defined using square brackets [], while tuples are defined using parentheses ().

• Lists are typically used for collections of similar items, while tuples are used for collections of different items.

• Example of a list: my_list = [1, 2, 3]

• Examp...read more

OOP concepts are foundational principles in programming that enable code reusability and organization through objects and classes.

• Encapsulation: Bundling data and methods that operate on the data within one unit (e.g., a class).

• Inheritance: Mechanism where a new class derives properties and behavior from an existing class (e.g., a 'Dog' class inheriting from an 'Animal' class).

• Polymorphism: Ability to present the same interface for different data types (e.g., a function that ...read more

Machine learning is a subset of artificial intelligence that enables systems to learn from data and improve over time without explicit programming.

• Machine learning algorithms can be supervised (e.g., predicting house prices) or unsupervised (e.g., clustering customers).

• Common algorithms include decision trees, neural networks, and support vector machines.

• Applications range from image recognition (e.g., facial recognition) to natural language processing (e.g., chatbots).

• Machin...read more