MS-DS Master of Data science FREE Master of Data Science Research & Data Analysis Questions and Answers 2

Question 1

A data scientist wants to determine whether a new recommendation algorithm increases user engagement compared to the existing one. Which experimental design is most appropriate?

Accepted Answer

A/B testing with random user assignment

Answer

A/B testing with random assignment allows causal inference by controlling for confounding variables between the treatment and control groups.

Question 2

When performing exploratory data analysis on a dataset with 50 features, which technique is most useful for identifying multicollinearity before building a regression model?

Accepted Answer

Variance Inflation Factor (VIF) analysis

Answer

VIF quantifies how much the variance of a regression coefficient is inflated due to multicollinearity among predictors.

Question 3

A researcher notices that their linear regression model has residuals that fan out as predicted values increase. What assumption is being violated?

Accepted Answer

Homoscedasticity

Answer

Residuals that fan out indicate heteroscedasticity, meaning the variance of errors is not constant across predicted values.

Question 4

In a master's thesis analyzing healthcare data, which method best handles missing data when the missingness mechanism is Missing at Random (MAR)?

Accepted Answer

Multiple imputation

Answer

Multiple imputation generates several plausible datasets, accounts for uncertainty in the missing values, and produces valid statistical inferences under MAR.

Question 5

A data science graduate student is presenting research findings and reports a p-value of 0.03 with a confidence interval of [-0.5, 12.3] for the treatment effect. What is the most valid interpretation?

Accepted Answer

The result is statistically significant but the wide interval suggests low practical precision

Answer

While the p-value indicates statistical significance at the 0.05 level, the wide confidence interval spanning near-zero to 12.3 indicates considerable uncertainty about the true effect size.

MS-DS Master of Data science Practice Test

MS-DS Master of Data science Practice Test

MS-DS Master of Data science FREE Master of Data Science Research & Data Analysis Questions and Answers 2