Mathematics
Kernel Density Estimation and Nonparametric Inference
Quick fact
Kernel density estimation can recover multi-modal distributions—like two peaks—that histograms often blur, yet it requires no assumption about the data's distributional family.
Why this is interesting
You have a pile of height measurements and you suspect there are two hidden groups. A simple average hides them—so how can you let the data show you the shape of the distribution?