MS-DS Master of Data science Master of Data Science 3

Question 1

In Apache Spark, what is the key difference between a transformation and an action?

Accepted Answer

Transformations are lazy and return RDDs; actions trigger execution and return results

Answer

Spark transformations (like map, filter) are lazy and only define a computation graph, while actions (like collect, count) trigger actual execution.

Question 2

Which technique is used to handle missing data by filling in plausible values based on observed data relationships?

Accepted Answer

Multiple imputation

Answer

Multiple imputation replaces missing values with several plausible estimates drawn from the observed data distribution, preserving statistical relationships.

Question 3

What is the primary purpose of the attention mechanism in transformer models?

Accepted Answer

To allow the model to weigh the importance of different tokens when encoding each token

Answer

The attention mechanism computes a weighted sum of value vectors, where weights reflect how relevant each position is to the current token being processed.

Question 4

In hypothesis testing, what does a p-value of 0.03 indicate?

Accepted Answer

There is a 3% chance of observing results this extreme if the null hypothesis is true

Answer

The p-value is the probability of obtaining a test statistic at least as extreme as observed, assuming the null hypothesis is true.

Question 5

Which data structure is most efficient for implementing a priority queue?

Accepted Answer

Binary heap

Answer

A binary heap supports O(log n) insert and extract-min/max operations, making it the standard choice for priority queue implementations.

MS-DS Master of Data science Practice Test

MS-DS Master of Data science Practice Test

MS-DS Master of Data science Master of Data Science 3