Data Science

caret

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Point out the correct statement.
The difference between the class centroids and the overall centroid is used to measure the variable influence
The Bagged Trees output contains variable usage statistics
Boosted Trees uses different approach as a single tree
None of the mentioned
Explanation:
The larger the difference between the class centroid and the overall center of the data, the larger the separation between the classes.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Point out the wrong statement.
The trapezoidal rule is used to compute the area under the ROC curve
For regression, the relationship between each predictor and the outcome is evaluated
An argument, para, is used to pick the model fitting technique
All of the mentioned
Explanation:
An argument, nonpara, is used to pick the model fitting technique.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
The function preProcess estimates the required parameters for each operation.
True
False
Explanation:
predict.preProcess is used to apply them to specific data sets.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
caret stands for classification and regression training.
True
False
Explanation:
The caret package is a set of functions that attempt to streamline the process for creating predictive models.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
For most classification models, each predictor will have a separate variable importance for each class.
True
False
Explanation:
The exceptions are classification trees, bagged trees and boosted trees.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Which of the following can be used to generate balanced cross–validation groupings from a set of data?
createFolds
createSample
createResample
none of the mentioned
Explanation:
createResample can be used to make simple bootstrap samples.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
Which of the following function can create the indices for time series type of splitting?
newTimeSlices
createTimeSlices
binTimeSlices
none of the mentioned
Explanation:
Rolling forecasting origin techniques are associated with time series type of splitting.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
Which of the following model model include a backwards elimination feature selection routine?
MCV
MARS
MCRS
All of the mentioned
Explanation:
MARS stands for Multivariate Adaptive Regression Splines.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Point out the wrong statement.
In every situation, the data generating mechanism can create predictors that only have a single unique value
Predictors might have only a handful of unique values that occur with very low frequencies
The function findLinearCombos uses the QR decomposition of a matrix to enumerate sets of linear combinations
All of the mentioned
Explanation:
In some situations, the data generating mechanism can create predictors that only have a single unique value.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
The advantage of using a model-based approach is that is more closely tied to the model performance.
True
False
Explanation:
Model-based approach is able to incorporate the correlation structure between the predictors into the importance calculation.