that can allow us to eliminate selection bias and estimate the treatment effect? Examples:
   - Experimentally vary `\(T\)`.
   - Eliminate "bad" variation in `\(T\)` (e.g., by controlling for enough other variables).
   - Isolate "good" variation in `\(T\)` (e.g., by finding and using an instrumental variable).


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class: inverse, middle
name: which

# Descriptive, Predictive, or Causal?

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# Types of goals

Now we can revisit our 3 goals of data analysis.

For sake of illustration, consider a simple 