Why squared error?
Drag a fitted line and compare absolute vs squared error live — see why least squares reacts so strongly to outliers.
Launch →STANDALONE MATERIALS
Interactive
Learning Lab
A separate home for interactive HTML modules. Each module can have a permanent URL and can be used independently of book chapter order.
Where distributions come from
Run coin-flip trials and watch a bell-shaped histogram emerge from raw randomness, not a formula.
Launch →Correlation vs causation
Same correlation number, four different causal stories — see why the number alone never settles which is true.
Launch →Pearson's correlation coefficient
Drag points and watch r update live — see the formula itself as a balance of agreeing vs disagreeing deviations.
Launch →Statistics · Mathematics · AI
The same system can serve every future STEM book.