If you've ever completed -- or helped your kids with -- a science fair project, you probably remember learning that your hypothesis should be a testable statement that can be supported or refuted through experimentation. But in everyday speech, we often use the word hypothesis to describe an educated guess. The two aren't entirely unrelated: Like an educated guess, a hypothesis is based on logic, observation and maybe even intuition, but the most important characteristic of a hypothesis is that it can be tested and the test, in turn, can be replicated.
A hypothesis is a scientist's attempt to provide a solution or explanation for a phenomenon that has not yet been explained [source: Zimmerman]. Of course, after reading the first scientific term on our list, you know that in science, a hypothesis is never "proved" to be correct; it's simply supported or refuted through repeated experimentation and observation – sometimes several decades' worth.
In the scientific method, a hypothesis is just the very first baby step toward formulating the next term on our list.