

Connections
• Exploratory Data Analysis
 Like the last unit, this unit provides tools to answer
questions about the relationships between two numerical variables in a
given data set using numerical and graphical summaries.
 As discussed in Unit 1, correct interpretation of the
summaries and the model outputs are key. In this unit, students must
especially be aware of how to do this for transformed variables. But in
general, students should be aware of the variables and observational
units in question.
 As discussed in the previous unit, later in the course, we
will learn to determine if apparent linear associations might be due to
chance just as we would like to determine whether differences between
groups (as covered in Unit 1) are due to chance.
• Models
 This unit continues the discussion of statistical models
and specifically discusses in more detail the idea of model selection.
 Like in the last unit, students will have trouble with this
abstractness of theoretical models and, in this unit, particularly with
the idea of interpreting models in the context of transformed or
aggregate variables. As mentioned in the last unit, introducing this
early might help alleviate that confusion for upcoming units dealing
with probability and simulation models.
