Free Master of Data Science Machine Learning Questions and Answers

Question 1

Which of the following can be used to a collection of data to produce balanced cross-validation groupings?

Accepted Answer

createFolds

Answer

In R's `caret` package, the `createFolds` function is specifically designed to generate balanced cross-validation folds. It partitions the data into `k` folds, ensuring that the class distribution (for classification problems) is approximately maintained within each fold, which is crucial for robust model evaluation. This helps prevent bias in the training and testing sets.

Question 2

Identify the incorrect statement.

Accepted Answer

Simple random sampling of time series is probably the best way to resample times series data.

Answer

Simple random sampling is generally inappropriate for time series data because it disrupts the inherent temporal dependencies and autocorrelation. Time series data has a sequential order, and random sampling would destroy this structure, leading to invalid models and predictions. Resampling methods for time series must preserve the chronological order.

Question 3

Which of the subsequent functions can be used to maximize the minimal differences?

Accepted Answer

sumDiss

Answer

In the context of selecting diverse samples, particularly with functions like `maxDissim` in R's `caret` package, `sumDiss` refers to maximizing the sum of dissimilarities between selected samples and a reference set. This approach aims to ensure that the chosen samples are as different from each other as possible, thereby maximizing the minimal differences and promoting diversity within the subset.

Question 4

Which of the following functions is capable of producing the indices needed for the time series splitting type?

Accepted Answer

createTimeSlices

Answer

In R's `caret` package, the `createTimeSlices` function is specifically designed to generate indices for time series cross-validation. It creates training and testing sets that respect the temporal order of the data, which is essential for accurate evaluation of models on time series. This function ensures that the test set always follows the training set chronologically.

Question 5

Which of the aforementioned functions wraps various lattice graphs to display the data?

Accepted Answer

featurePlot

Answer

The `featurePlot` function in R's `caret` package is a versatile tool for visualizing relationships between features (predictor variables) and the outcome variable. It wraps various `lattice` graphics functions to create different types of plots, such as scatter plots, box plots, and density plots, allowing for comprehensive exploration of data characteristics and relationships. It simplifies the process of generating informative visualizations.

MS-DS Master of Data science Practice Test

MS-DS Master of Data science Practice Test

Free Master of Data Science Machine Learning Questions and Answers