"Few things are more nerve-racking than speaking off the cuff," says executive coach Melody Wilding. Here's how to handle unexpected questions with poise.

Figure 1: (A) Schematic of a fiber-optic DNA microarray. In this illustration microspheres functionalized with DNA sensing chemistry are randomly distributed on an optical imaging fiber surface. As ...

Learn the distinctions between simple and stratified random sampling. Understand how researchers use these methods to accurately represent data populations.