DMC DMC Statistical Methods & Data Mining Concepts

Question 1

What does the correlation coefficient measure in data mining?

Accepted Answer

The strength and direction of the linear relationship between two variables

Answer

The average value of a dataset

Answer

The number of outliers in a dataset

Answer

The variance of a single variable

Question 2

Which measure of central tendency is LEAST affected by extreme outliers?

Accepted Answer

Median

Answer

Mean

Answer

Mode

Answer

Range

Question 3

In hypothesis testing, a p-value less than 0.05 typically indicates:

Accepted Answer

The result is statistically significant

Answer

The null hypothesis should be accepted

Answer

The sample size is too small

Answer

There is no correlation between variables

Question 4

What is 'overfitting' in the context of data mining models?

Accepted Answer

A model that performs well on training data but poorly on new data

Answer

A model with too few parameters to learn patterns

Answer

A model that consumes excessive memory during training

Answer

A model that consistently underpredicts output values

Question 5

Which statistical technique reduces the number of variables while retaining most of the dataset's variance?

Accepted Answer

Principal Component Analysis (PCA)

Answer

Regression analysis

Answer

Naive Bayes classification

Answer

Association rule mining

Question 6

What is the purpose of cross-validation in data mining?

Accepted Answer

To assess how well a model generalizes to independent datasets

Answer

To validate database schema integrity

Answer

To cross-reference records across two databases

Answer

To check source data for duplicate entries