Exercises

1. Rerun the first model using the petal length and then petal width variables. What are the main differences in the results? How wide or narrow is the 95% HPD interval in each case?
2. Repeat exercise 1, this time using a Student's t-distribution as a weakly informative prior. Try different values of .
3. Go back to the first example, the logistic regression for classifying setosa or versicolor given sepal length. Try to solve the same problem using a simple linear regression model, as we saw in Chapter 3, Modeling with Linear Regression. How useful is linear regression compared to logistic regression? Can the result be interpreted as a probability? Tip, check whether the values of are restricted to the [0, 1] interval.

4. In the example from the Interpreting the coefficients of a logistic regression section, we changed sepal_length by 1 unit. Using Figure 4.6, corroborate...