The data preparation is made in the data_preparation function. Other functionalities of my code are separated into several functions:

• run_all_models: runs all 3 models and returns its results and graphs
• correlation_matrix: returns the correlation matrix of the data
• linear_regression_feature_importance: returns an experimental measurement of linear regression feature importance
• count_feature_occurrence: returns an measurement of count feature occurrence
• variance_by_question_type: returns the variance of the task by question type