MS-DS Master of Data science Research & Data Analysis 2

Question 1

A researcher wants to determine whether a new teaching method improves test scores compared to a traditional method. Which study design is most appropriate?

Accepted Answer

Randomized controlled experiment

Answer

A randomized controlled experiment allows causal inference by randomly assigning participants to treatment and control groups.

Question 2

In hypothesis testing, a p-value of 0.03 with a significance level of 0.05 means:

Accepted Answer

Reject the null hypothesis

Answer

Since 0.03 < 0.05, the result is statistically significant and we reject the null hypothesis.

Question 3

Which technique is used to assess the stability of a regression model by partitioning data into training and validation subsets multiple times?

Accepted Answer

K-fold cross-validation

Answer

K-fold cross-validation splits data into k subsets and iteratively trains/validates across all folds to estimate model performance.

Question 4

A dataset has a mean of 50, median of 45, and mode of 40. This distribution is best described as:

Accepted Answer

Positively skewed

Answer

When mean > median > mode, the distribution has a longer right tail, indicating positive (right) skew.

Question 5

A data scientist uses Lasso regression instead of OLS. The primary advantage of Lasso in high-dimensional data is:

Accepted Answer

It performs automatic feature selection by shrinking some coefficients to zero

Answer

Lasso's L1 penalty shrinks some coefficients to exactly zero, effectively selecting a sparse subset of predictors.

MS-DS Master of Data science Practice Test

MS-DS Master of Data science Practice Test

MS-DS Master of Data science Research & Data Analysis 2