What is Hypothesis? What are its types and characteristics?

“Hypothesis may be defined as a proposition or a set of propositions set forth as an explanation for the occurrence of some specified group of phenomena either asserted merely as a provisional conjecture to guide some investigation in the light of established facts” (Kothari, 1988).

A research hypothesis is quite often a predictive statement, which is capable of being tested using scientific methods that involve an independent and some dependent variables. For instance, the following statements may be considered:

  • “Drinking sugary drinks daily leads to obesity” or,
  • “The female students perform as well as the male students”.

These two statements are hypotheses that can be objectively verified and tested. Thus, they indicate that a hypothesis states what one is looking for. Besides, it is a proposition that can be put to test in order to examine its validity.

Types of hypothesis

Hypotheses are of two types,

Null hypothesis
Alternative hypothesis

When two methods A and B are compared on their relative superiority, and

  • It is assumed that both the methods are equally good, then such a statement is known as the null hypothesis. A null hypothesis exists when a researcher believes there is no relationship between the two variables, or there is a lack of information to state a scientific hypothesis. This is something to attempt to disprove or discredit.
  • On the other hand, if method A is considered relatively superior to method B, or vice-versa, then such a statement is known as an alternative hypothesis. In an attempt to disprove a null hypothesis, researchers will seek to discover an alternative hypothesis.

The null hypothesis is expressed as H0, while the alternative hypothesis is expressed as H1.


A hypothesis should have the following characteristic features

  1. It must be precise and clear. If it is not precise and clear, then the inferences drawn on its basis would not be reliable.
  2. A hypothesis must be capable of being put to test. Quite often, the research programmes fail owing to its incapability of being subject to testing for validity. Therefore, some prior study may be conducted by the researcher in order to make a hypothesis testable. A hypothesis “is tested if other deductions can be made from it, which in turn can be confirmed or disproved by observation” (Kothari, 1988).
  3. It must state the relationship between two variables, in the case of relational hypotheses.
  4. It must be specific and limited in scope. This is because a simpler hypothesis generally would be easier to test for the researcher. And therefore, he/she must formulate such hypotheses.
  5. As far as possible, a hypothesis must be stated in the simplest language, so as to make it understood by all concerned. However, it should be noted that the simplicity of a hypothesis is not related to its significance.
  6. It must be consistent and derived from the most known facts. In other words, it should be consistent with a substantial body of established facts. That is, it must be in the form of a statement which is most likely to occur.
  7. It must be amenable to testing within a stipulated or reasonable period of time. No matter how excellent a hypothesis, a researcher should not use it if it cannot be tested within a given period of time, as no one can afford to spend a lifetime on collecting data to test it.
  8. A hypothesis should state the facts that give rise to the necessity of looking for an explanation. This is to say that by using the hypothesis, and other known and accepted generalizations, a researcher must be able to derive the original problem condition. Therefore, a hypothesis should explain what it actually wants to explain, and for this, it should also have an empirical reference.

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Author and Assistant Professor in Finance, Ardent fan of Arsenal FC. Always believe "The only good is knowledge and the only evil is ignorance - Socrates"
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