A hypothesis is a tentative generalization, the validity of which has got to be tested. A hypothesis, at its initial stage, may be an imagined idea of mere guess. It is based on accumulated previous knowledge. It is made in order to find out the correct explanation of a phenomenon through investigation. On the basis of the hypothesis, facts are observed and collected. When by verification, the hypothesis is found to be true, a theory is obtained.

Functions

1.         The most important function of a hypothesis is to adequately explain all the facts connected with the hypothesis.

2.         It enables us to direct enquiry along the right lines. It suggests experiments and observation. It helps to collect necessary evidences in order to discover the order of nature.

3.         Hypothesis determines the method of verification as well as the procedure for enquiry. Hypothesis limits the scope of enquiry to a manageable area, because, instead of random collection of data, it enables us to search only for relevant facts. Therefore, it leads to economy of time and money.

4.         It leads to the discovery of laws. It explains facts and laws, and thus seeks to verify knowledge.

5.         Hypothesis leads to conclusion, which is sometimes very significant for the advancement of knowledge. The significances of an object or event can be determined by a hypothesis.

According to Northrop, “The function of a hypothesis is to direct our search for other among facts. The suggestions formulated in any hypothesis may be solution to the problem. Whether they are, is the task of the enquiry.”

Conditions for a Valid Hypothesis

1.         The most important condition for a valid hypothesis is that it should be empirically verifiable. A hypothesis should be compared with the facts of experience directly or indirectly. A hypothesis has ultimately got to be confirmed or refuted; otherwise, it will remain a mere supposition.

2.         A hypothesis must provide answer to the problem, which initiated enquiry.

3.         A false hypothesis is not always useless. It may encourage further investigation and attempt to find out relations among facts and thereby, may increase the evidence for other theories.

4.         In case we have more than one hypothesis, we should prefer the one, which has a strong power of, predictability and which can explain the consequences.

5.         If there are two hypotheses on the same problem and if they can be equally confirmed by evidence, the simpler hypothesis is generally chosen. A hypothesis is simpler than, the other, if the first is more general in nature and has fewer assumptions and a smaller number of independent elements. But simplicity should not be confused with familiarity. A new and unfamiliar hypothesis should never be adopted merely for its simplicity.

6.         A valid hypothesis generally does not go against the traditionally established knowledge. But a hypothesis may not always be invalid, if it goes against well-established knowledge; for the traditional knowledge may itself be wrong.

7.         A hypothesis must be clear, definite and certain. It should not be vague or ambiguous.

8.         A valid hypothesis suggests on explanation, which appears reasonably true in the present state of knowledge. A fanciful idea or an absurd imagination does not make a valid hypothesis.

Formulation of Hypothesis

There is no definite set of rules, which can be laid down for the formulation of hypothesis. Partly, it is a matter of hitting upon an idea on some problem. According to stebbing, “every hypothesis springs from the union of knowledge and sagacity.” Previous knowledge of the field of enquiry plays a significant part for the formulation of hypothesis. A hypothesis must take some facts as significant. A relevant hypothesis expresses determinate modes of connections between a set of facts, including the fact investigated. However, scientific procedure in this regard plays an important role. However, one must be fully acquainted with the facts and theories already existing in respect of the phenomenon with which one is engaged. The possession of such knowledge depends to a grant extent on one’s experience and insight.

Verification and proof of hypothesis

Verification of hypothesis means the testing of the truth of the hypothesis in the light of facts. For verification, there must be an agreement between the interference of the hypothesis and the observed facts. The greater the agreement, the stronger is the hypothesis. Direct verification means the direct appeal to the fact of experience through simple observation or experiment. Where a hypothesis cannot be directly verified, it should be verified indirectly. In indirect verification, the consequences deduced from the hypothesis are compared to the facts. If there is an agreement between consequences and facts, a hypothesis is verified. If facts agree with the hypothesis and, is no contradictory fact, the hypothesis is verified.

However, verification is not conclusive proof. A hypothesis must adequately explain all facts for which it has been made, and it must be the only hypothesis to do so. It must also explain all related facts, and it should have the power of prediction.

Sometimes two or more hypothesis may explain facts. Then in order to know which one of them provides the real explanation, we take a crucial instance. This can be found out by observation or by experiment. A crucial instance is an instance, which can only be explained by one of the contending hypothesis, and not by the other. This instance not only confirms a hypothesis, but it also negates the other. Suppose that a hypothesis is that X has committed a theft, another hypothesis is that Y has committed the theft. In course of investigation, it is found that X was present at a very distant place at the time when the theft was committed. Then, this is a crucial instance.