Machine Learning Practice Test

Question 1

We set the gradient to zero to obtain the minimum or maximum of a function because:

Accepted Answer

The value of the gradient at extrema of a function is always zero

Answer

Explanation:
The gradient of a multivariable function at a maximum point will be the zero vector of the function, which is the single greatest value that the function can achieve.

Question 2

Which of the following machine learning algorithms is based on the principle of bagging and is extensively used and effective?

Accepted Answer

Random Forest

Answer

Explanation:
The Radom Forest algorithm builds an ensemble of Decision Trees, mostly trained with the bagging method.

Question 3

Which of the following is a good characteristic of a test dataset?

Accepted Answer

A and B

Answer

Explanations:
A good test dataset has a good amount of sample population and equal ratios of class representation.

Question 4

The following are the most regularly used metrics and tools for evaluating a classification model:

Accepted Answer

All of the above

Answer

Explanations:
The model performance assessment for classification algorithms encorporates all of the above techniques.

Question 5

What is the purpose of cross-validation?

Accepted Answer

Both A and B

Answer

Explanations:
Cross-validation is a model validation technique for assessing how the results of a statistical analysis will generalize to an independent data set.