The hypotheses must be specific. One may hypothesize that something will happen in next five minutes, with absolute confidence but just because it is refuted it is empty of concrete information. We need to know what will happen and as soon as we commit ourselves to one view or another we become vulnerable; our prediction will be refuted if what was said would happen does not happen.
A scientific statement is useful to the extent it allows itself to be exposed to a possible refutation. Often the researchers are tempted to express their hypotheses in terms so general and so grandiose in scope that they are simply not amenable to test.
This temptation can be suicidal. The researchers would do well to avoid employing concepts in their hypotheses for which suitable tangible indices have not developed. An hypothesis should include a clear statement of indexes which are to be used. For example, the concept of social class needs to be explicated in terms of such indicators as income, occupation, education, etc.
Such specific formulations have the obvious advantage of assuring that research will be practicable and significant. It also helps to increase the validity of the results because more specific the statement or prediction, smaller the probability that it will actually be borne out as a result of mere accident or chance.