• Say its the early 1900's, and you are a statistician and you meet someone who claims to be able to tell by tasting whether the tea or the milk was added first to a cup.
• You call BS and think they are just guessing.
• Say you have 8 cups, tea, and milk handy. How would you design an experiment to test whether a) they can really tell which came first or b) they are just guessing?
• Brainstorm all the components of this experiment with your seatmates. To revisit later: Then think about how you can implement this with resampl()ing.

Let's pick some pods at random…

We'll view randomness in this course largely through two lenses:

See blackboard notes.

A medical doctor pours over some his patients' medical records and observes:

People who do this:	Wake up with this:

He then asserts the following causal relationship:

• Explanatory AKA treatment variable: sleeping with shoes on
• Response variable: causes one to wake up with a headache

What's wrong?

See blackboard notes.

Correlation is not necessarily causation:

• Spurious correlations
• Organic food causes autism!
• Does college cause higher earnings? See blackboard diagram.

See blackboard notes.

• Making causal statements with observational studies is harder because you need to control for (account for) all possible confounding variables; in this case alcohol.
• But you may not have access to all confounding variables.
• Prof. Caitlin Myers' "ECON 212 Empirical Economic Research" this Spring will study methods that attempt to make causal statements despite only having observational data.

• The treatment, sleeping with shoes on, was NOT assigned at random; we have an observational study.
• We can't assert causation, but only association/correlation

• Instead
• Say for each patient you have two variables: 1) whether they slept with shoes on and 2) whether they woke up with a headache
• To assert causality, we would need a randomized experiment!

See blackboard notes.

I went to grad school in Seattle, where Garfield High School is located. Famous alums include:

• Quincy Jones: Producer and composer
• Jimi Hendrix: Guitarist
• Brandon Roy: Former NBA Rookie of the Year
• Macklemore: Rapper
• Minoru Yamasaki: World Trade Center architect

Next door is Ezell's Fried Chicken. Oprah Winfrey apparently has it flown into to Chicago.

One day I was raving about Ezell's Chicken. My friend Nick accused me "buying into the hype".

So what did we do?

Fried Chicken Face Off:

Do people prefer this?	Or this?

Say you have 12 grad students eager to procrastinate, how would you design a taste test to ascertain, independent of hype, which fried chicken tastes better?

Use the relevant principles of designing experiements from above.