Do the variables tend to change together?
Things look correlated
Things look correlated
Do the variables tend to change together?
Correlation = 0.94
What your brain does
Can you use the data to make predictions?
Where should the line should go?
Regression
Where should the line should go?
Minimize distance to line
Fit of data to line: 0.88 Slope: 2.05 Intercept: 4.23
How the computer minimizes distance
Take a guess at a line that fits the data
How the computer minimizes distance
Measure distance to points
How the computer minimizes distance
Take lots of guesses
Minimizing distance to line
Here are some lines that are close
Modeling more variables
Modeling more variables
Modeling more variables
Modeling more variables
