The pooled estimator is a mixture of the group variances, placing greater weight on whichever has a larger sample size.

Which statistical test is used to determine if there is a significant association between two categorical variables?

A. Chi-squared test

B. T-test

C. ANOVA

D. Regression analysis

In the context of data ethics, what does "bias mitigation" refer to?

A. Increasing the sample size

B. Improving model accuracy

C. Removing outliers from a dataset

D. Reducing biases in data collection

What does the term "overfitting" mean in machine learning?

A. The model fits the training data too closely and performs poorly on new data

B. The model generalizes well to new data

C. The model is too simple and underperforms on the training data

D. The model is perfectly accurate on all data

In the CRISP-DM data mining process model, what does "DM" stand for?

A. Data Modeling

B. Data Mining

C. Data Manipulation

D. None of the above