structural testing

A three-minute Emacs Rocks screencast by Magnar Sveen demonstrating paredit, which edits Lisp code structurally as a tree of s-expressions rather than characters.

Matt Risinger demonstrates a blower door test on a house, using a fan to measure air leakage and find where air gets in and out. It shows how the test reveals the quality of the build.

The UK DVSA's one-minute guide to the hazard perception part of the driving theory test, covering when to click and how to score well.

Jeri Ellsworth shows early steps of making microchips at home: cleaving wafers, removing native oxide, testing dopant type with a hot probe, and loading the furnace.