What are the criteria for a testable hypothesis?

Answer 1

Basically, is it repeatable?

Like, that's why many miracles can't be proven scientifically. If somebody gets a grilled cheese sandwich with Mary's face on it...how are you going to repeat that?

It has to be repeatable by anybody under the same circumstances.

Answer 2

I've been told that it has three parts: an "If", "then," and "because."

ex.: If a piece of gum is chewed, then it will only be 15% sugar because bubble gum is supposed to be less sticky than regular chewing gum in order to be able to blow bubbles.

The "because" is the hardest part to come up with.