2. Introduction
• The word hypothesis consists of two words – Hypo+Thesis, ‘Hypo’ means tentative or
subject to the verification, ‘Thesis’ means statement about solution of the problem.
• Thus the literal meaning of the term hypothesis is a tentative statement about the
solution of the problem.
• Hypothesis offers a solution of the problem that is to be verified empirically and based
on some rationale.
• Hypothesis is a temporary explanation, a kind of educated guess about what will
happen under certain conditions
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3. Functions of Hypothesis
• It is a temporary solution of a problem concerning with some truth
which enables an investigator to start his research works.
• It offers a basis in establishing the specifics what to study for and may
provide possible solutions to the problem.
• It may lead to formulate another hypothesis.
• A preliminary hypothesis may take the shape of final hypothesis.
• It defines field of the investigation.
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4. Functions of Hypothesis
• Each hypothesis provides the investigator with definite statement
which may be objectively tested and accepted or rejected and
leads for interpreting results and drawing conclusions that is
related to original purpose.
• It sensitizes the researcher so that he should work selectively, and
have very realistic approach to the problem.
• It offers the simple means for collecting evidences for verification.
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5. Importance of a Hypothesis
• Investigator’s eyes: Guiding the investigator in further investigation hypothesis serves as the
investigator’s eyes in seeking answers to tentatively adopted generalization.
• Focuses research: Without hypothesis, a research is unfocussed research and remains like a
random empirical wandering. Hypothesis serves as necessary link between theory and the
investigation.
• Clear and specific goals: A well thought out set of hypothesis places clear and specific goals before
the research worker and provides him with a basis for selecting sample and research procedure to
meet these goals.
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6. Importance of a Hypothesis
• Links together: “It serves the important function of linking together related facts and
information and organizing them into single.”
• Prevents blind research: ”The use of hypothesis prevents a blind search and
indiscriminate gathering of masses of data which may later prove irrelevant to the
problem under study.“
• Guiding Light: ”A hypothesis serves as powerful encouragement that lights the way for
the research work.”
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7. Formulation of Hypothesis
Hypothesis must be formulated after comprehensive literature review.
Hypothesis formulated afterwards shall be considered a strong hypothesis.
A poorly chosen or poorly expressed hypothesis can prevent the following:
• The obtaining of enough pertinent data,
• The drawing of conclusions and generalizations
• The application of certain statistical measures in the analysis of the result.
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8. Types/Forms of Hypothesis
• Question form
• Declarative Statement
• Directional Hypothesis
• Non –Directional/Null Hypothesis
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9. Question form
• A hypothesis stated as a question represents the simplest level of empirical
observation.
• It fails to fit most definitions of hypothesis.
• There are cases of simple investigation which can be adequately
implemented by raising a question, rather than dividing the hypothesis into
forms into acceptable / rejectable categories.
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10. Declarative Statement
• A hypothesis developed as a declarative statement provides an anticipated
relationship or difference between variables.
• Such a hypothesis developer has examined existing evidence which led
him to believe that a difference may be anticipated as additional evidence.
• It is merely a declaration of the independent variables effect on the
criterion variable.
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11. Directional Hypothesis
• A directional hypothesis denotes an expected direction in the relationship or difference between
variables.
• This type of hypothesis developer appears more certain of anticipated evidence.
• If seeking a capable hypothesis is the general interest of the researcher, this hypothesis is less safe
than the others because it reveals two possible conditions.
– First that the problem of seeking relationship between variables is so obvious that additional
evidence is scarcely needed.
– Secondly, researcher has examined the variables very thoroughly and the available evidence
supports the statement of a particular anticipated outcome.
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12. Non –Directional/Null Hypothesis
• This hypothesis is stated in the null form which is an assertion that no relationship or no difference
exists between or among the variables.
• Null hypothesis is a statistical hypothesis testable within the framework of probability theory.
• It is a non-directional form of hypothesis.
• There is a trend to employ or develop null hypothesis in research in most of the disciplines.
• A null hypothesis tentatively states that on the basis of evidence tested there is no difference.
• Statistical tests of significance are used to accept and reject the null hypothesis.
• If it is rejected, the general hypothesis is accepted
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13. Concepts concerning testing of hypotheses
• Null Hypothesis and Alternate Hypothesis
• Level of Significance
• Type-I Error and Type-II Error
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14. Null hypothesis and alternative hypothesis
• In the context of statistical analysis, we often talk about null hypothesis and alternative
hypothesis.
• If we are to compare method A with method B about its superiority and if we proceed on the
assumption that both methods are equally good, then this assumption is termed as the null
hypothesis.
• As against this, we may think that the method A is superior or the method B is inferior, we are
then stating what is termed as alternative hypothesis.
• The null hypothesis is generally symbolized as H0 and the alternative hypothesis as Hα.
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15. The level of significance
• This is a very important concept in the context of hypothesis testing.
• It is always some percentage (usually 5%) which should be chosen with great care & thought.
• In case we take the significance level at 5 per cent, then this implies that H0 will be rejected when
the sampling result (i.e., observed evidence) has a less than 0.05 probability of occurring if H0 is true.
• In other words, the 5 per cent level of significance means that researcher is willing to take as much as
a 5 per cent risk of rejecting the null hypothesis when it (H0) happens to be true.
• Thus the significance level is the maximum value of the probability of rejecting H0 when it is true and
is usually determined in advance before testing the hypothesis.
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16. Type I and Type II errors
• While testing a hypotheses, there are basically two types of errors we can make.
• We may reject H0 when H0 is true and we may accept H0 when in fact H0 is not true.
• The former is known as Type I error and the latter as Type II error.
• In other words, Type I error means rejection of hypothesis which should have been
accepted and Type II error means accepting the hypothesis which should have been
rejected.
• Type I error is denoted by α (alpha) known as α error, also called the level of significance
of test; and Type II error is denoted by β (beta) known as β error.
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