Psychology 202a
Advanced Psychological
Statistics
September 17, 2015
The Plan for Today
• Conditional distributions.
• Conditioning on continuous variables.
• Introducing the concept of random
variables and probability distributions.
Conditional distributions
• Systematically compare each aspect of the
shape of a distribution.
• Tools for doing this in SAS.
• Tools for doing this in R.
Conditional distributions
• What about conditioning on a continuous
variable?
• Ways to understand (don’t do this at
home)
– The infamous median split
– The quartile split
– Ad infinitum
• Scatterplots in R