Hypothesis is used as a step in the procedure of induction. Before the inductive generalization, usually a hypothesis is framed.

It is a stage of making a probable supposition. It is not the only use of hypothesis. Hypotheses are used very frequently by the natural scientists; it is also a probable supposition to explain certain facts or phenomena whose explanations are not known.

To explain and organise certain facts and to bring them under certain law is the very objective of the inductive procedure for which hypothesis is framed.

Hypothesis is thus, formulated to know the possible explanation, either causal or otherwise, of a phenomenon. When the cause or explanation of a phenomenon or a class of phenomena is not known or is not explainable with the existing knowledge, a hypothesis is formulated. It is the supposed or provisional explanation of the phenomenon.


Mill defines hypothesis as “any supposition which we make either without actual evidence or on evidence avowedly insufficient in order to endeavour to deduce from it conclusions in accordance with facts which are known to be real under the idea that if the conclusions to which the hypothesis leads, are known truths, the hypothesis itself either must be, or at least is likely to be true.”

It is a definition of hypothesis that tells us what a hypothesis should be.

Coffey defines hypothesis to be “an attempt at explanation, a provisional supposition made in order to explain scientifically some fact or phenomenon”. Stebbins expresses it as ‘a hypothesis is a proposition suggested by the evidence available to establish the conclusion but insufficient to demonstrate the conclusion’. Hypotheses are framed when we seek to ask why something has happened. A hypothesis is, thus, considered to be a supposition for the possible explanation of facts.

Let us take one example to explain it. Suppose one day at a particular time when we arrive at the station to board the train, we do not find the heavy crowd on the platform which normally should have been there during the time of the departure of the train.


It puzzles us. We try to know the reason. Here a possible explanation comes to the mind that perhaps there is rail-strike somewhere for which the trains are cancelled. Or may be there is some derailment for which the schedule has been changed.

Such explanations are different attempts to remove the puzzlement. After inquiry or verification we can be sure of the reason.

Modern logicians prefer the term ‘ explanation’ in place of ‘hypothesis’. Logicians, Copi and Cohen, have given the definition of an explanation in the following manner: “An explanation is a group of statements or a story from which the thing to be explained can logically be inferred and whose acceptance removes or diminishes its problematic or puzzling character”.

The explanations may be concerning scientific truths or may be concerning the facts of everyday life. Accordingly there are two types of explanations, namely, scientific and unscientific.


Characteristics of hypothesis:

i) Hypothesis is an attempt at an explanation of certain puzzled facts. It is the attempt to find out the possibility of the occurrence of such a fact. Sometimes it is framed to explain certain scientific truth or to explain a law.

ii) It is a probable explanation or presupposition of a cause. If the cause of an event is not known, the investigation starts with a probable cause. For example, if we perceive the effect of an accident and the cause is not witnessed, then the possible reasons of the accident are thought of for investigations.

iii) No hypothesis is certain or definite at the stage of assumption. It is merely probable. It may be framed without evidence or evidence avowedly insufficient. So it requires verification for confirmation.


iv) Through hypothesis facts are organized in a systematic manner. The aim of hypothesis is to reach at the real explanation and to remove the puzzlement concerning the event.

It is possible through systematization of involved facts. In this way very often hypothesis is framed to explain a law.

v) Formation of hypothesis is keenly connected with the verification of it. Hypothesis is found in the form of a conclusion.

It is compared with the known facts to decide whether such a conclusion can be deduced. If so the relevance of the hypothesis is accepted. Logical form of a hypothesis.


E (effect) is due to either h1 or h2 or h3 or h4.

not h1 (If hi then A, But not A, not h1)

not h2 (If h2 then B, But not B, not h2).

not h3 (If hi then C, But not C, not h3).


Since E is not due to h( h2or h3 E is due to h4. This logical form is applicable if the number of causes of a hypothesis is fixed.