James Schlatter, a research chemist working to develop an anti-ulcer drug, inadvertently got some of the substance on his fingers. When he later licked his fingers to pick up a piece, his fingers tasted very sweet, and he correctly linked the sweetness back to the anti-ulcer drug. Instead of finding an anti-ulcer drug, he discovered aspartame (NutraSweet), now the dominant commercial artificial sweetener. Purpose:

Hypothesis:

Controlled variables:

Independent variable:

Dependent variable: