Unit4, Section4: Decisions, Decisions
Instructional Days: 3
Enduring Understandings
Decision trees are used to classify observations into similar groupings based on known characteristics. Yes/no questions are asked, then the observations are sorted based on the responses to the questions. After a specified number of iterations, a final group membership is decided. One particular modeling tool we use for decision trees is known as CART (Classification and Regression Trees).
Engagement
Students will participate in the CART Activity described in Lesson 12. They will classify football and soccer players into categories based on player characteristics.
Learning Objectives
Statistical/Mathematical:
SIC 2: Decide if a specified model is consistent with results from a given datagenerating process, e.g., using simulation.
Data Science:
Understand that classification and regression trees can be used to predict membership in groups.
Applied Computational Thinking using RStudio:
• Create classification and regression trees.
RealWorld Connections:
Cardiologists may use a decision tree to diagnose whether people are or are not having a heart attack. Since the late 1870’s, this method has been found to correctly diagnose a heart attack in over 95% of cases compared to correct diagnoses based on individual doctors’ expertise, which ranged between 75 and 90%.
Language Objectives

Students will use complex sentences to construct summary statements about their understanding of data, how it is collected, how it is used, and how to work with it.

Students will engage in partner and whole group discussions and presentations to express their understanding of data science concepts.
Data File or Data Collection Method
Data File:
 Titanic: data(titanic)
Legend for Activity Icons