Gene speaks to the flowers in pot A for one hour every day, but not to the flowers in pot B. At the end of his experiment, Gene finds that the flowers in pot A grew faster than those in pot B. This leads him to the conclusion that plants grow faster when they are spoken to.

This can be described as assumption.

Explanation:

It should be understood that when a research is not scientifically proven with the right process,tools and other a normal or certain condition, it is described as an assumption.

In this case, Gene outcome about the plants can only be concluded as assumption because it is not proven by scientific processes or procedures.