A hypothesis is a hunch, assumption, suspicion, assertion or idea about a phenomenon, relationship or situation, which you intend to investigate in order to find out if you are right. If it proves to be right, your assumption was correct; hence, you prove that your hypothesis was true. Otherwise, you conclude your hypothesis to be false.
Disproving a hypothesis is as important as, or more important than, proving it. As a hypothesis is usually constructed on the basis of what is commonly believed to be right, your disproving it might lead to something new that has been ignored by previous researchers.
A hypothesis should be conceptually simple, clear and specific, and be capable of verification and being expressed operationally.
There is a specific way of writing a hypothesis, with which you need to be familiar (refer to Chapter 6).