Application of the CART Model to Classify the Perception of Young Canadian Teenagers on the Effect of Marijuana on Health

Abstract

The use of the illicit drug, marijuana has increased over years among young teenagers in different parts of the world and its harm on the health is generally well-known. This paper attempts to study the perception of young adolescents of 13-15 years old residing in Canada towards the danger of marijuana on health. To do so, a classification and regression tree (CART) has been applied on the data from the 2012 National Anti-Drug Strategy (NADS) Youth Advertising Recall and Tracking Survey. The decision tree has been applied and pruned on a training data set (70%) and evaluated on the testing data set (30%). The results show that the main indicators which impact on the perception of a teenager towards the harm marijuana has on health are the perceptions towards psilocybin (another illicit drug), the province in which the teenager lives and whether he/she has been ever offered drugs. The overall error rate on the testing data set based on the confusion matrix is less than 20% and the area under the ROC curve is relatively high showing that the model is accurate in classifying the perception of young teenagers on the health marijuana has on health.