**DEFINITION OF HYPOTHESIS**

Hypotheses are single tentative guesses, good hunches – assumed for use in devising theory or planning experiments intended to be given a direct experimental test when possible”. (Eric Rogers, 1966)

A hypothesis is a conjectural statement of the relation between two or more variables”. (Kerlinger, 1956)

A research question is essentially a hypothesis asked in the form of a questionBasically hypothesis is a statement that is suggested by knowledge or observation but has not, yet, been proved or disproved.” (Macleod Clark J and Hockey L 1981)

In simple small words

**Hypothesis is**

**An educated guess**

A tentative point of view

A proposition not yet tested

A preliminary explaination

A preliminary Postulate

**NATURE OF HYPOTHESIS**

The hypothesis is a clear statement of what is intended to be investigated.

It should be specified before research is conducted and openly stated in reporting the results.

This allows to:

Ã˜ Identify the research objectives

Ã˜ Identify the key abstract concepts involved in the research

Ã˜ Identify its relationship to both the problem statement and the literature review

A problem cannot be scientifically solved unless it is reduced to hypothesis form

**FOR PROPOSING HYPOTHESIS**

You must make a prediction/ Statement/ postulation

you must identify at least two variables

Following qualities are needed in your hypothesis:

It should have an elucidating power

It should strive to have an acceptable explaination or accounting of a fact

It must be falsifiable simply: It must be capable of being refuted based on the results of the study

It must be formulated in simple, understandable terms

It should correspond with existing knowledge

In general, a hypothesis needs to be unambiguous, specific, quantifiable, testable and generalizable.

**CHARACTERISTICS OF HYPOTHESIS**

1. A Hypothesis must be conceptually clear

- concepts should be clearly defined

- the definitions should be commonly accepted

- the definitions should be easily communicable

2. The hypothesis should have empirical reference

- Variables in the hypothesis should be empirical realities

- If they are not it would not be possible to make the observation and ultimately the test

3. The Hypothesis must be specific

- Place, situation and operation

4. A hypothesis should be related to available techniques of research

- Either the techniques are already available or

- The researcher should be in a position to develop suitable techniques

5. The hypothesis should be related to a body of theory

- Hypothesis has to be supported by theoretical argumentation

- It should depend on the existing body of knowledge

**TYPES OF HYPOTHESIS**

**1. Based on their formulation**

Null Hypotheses and Alternate Hypotheses

**2. Based on direction**

Directional and Non-directional Hypothesis

**3. Based on their derivation**

Inductive and Deductive Hypotheses

But for all practical purposes we all need to know about the first one

**Null Hypotheses (Ho) and Alternate Hypotheses (H1) (The HO AND THE HI)**

**Null hypothesis always predicts that**

No differences between the groups being studied e.g., experimental (drinking) vs. control group (Non drinking) , No difference in these two groups when incidence of Driving accidents studied among them

**or**

No relationship between the variables being studied (eg. Drinking and Driving dont result in accidents)By contrast,

**the alternate hypothesis always predicts**that there will be a difference between the groups being studied (or a relationship between the variables being studied)

In fact in medical research, Frequently “alternative” is actual desired conclusion of the researcher!

( All we want is to establish that the Alternative hypothesis is true and that can be done by rejecting the null hypothesis)

In above eg, we want to reject that there is no association between drinking and driving accidents and hence we want to prove that there is in fact a relation. For this we conduct the study in two groups.

Formulate the H0 and H1

Collect data (Observation).

Apply statistical test, and

prove or disprove the null hypothesis.

Remember we dont do it, the other way. Meaning we dont reject or accept the alternative hypothesis.

How strong is that relation depends on statistical parameters like p value.

**EXAMPLE**

__Drug trial on a new drug__

H0: there is no difference between the two drugs on average

H1: the new drug is better than the current drug, on average.

**So,**

Ho relates to the statement being tested

H1 relates to the statement to be accepted if the null is rejected

The final conclusion - (Always in terms of Ho)

Accept H0 = No difference between old and new drug

Reject H1 = Difference between Old and new exist and is a fact

Lets simplify this

**Based on how it's derived, Hypothesis can ALSO be classified as**

**Inductive and Deductive Hypotheses**

**Inductive reasoning**is the more common way that scientists conduct experiments. Scientists have an idea of something to study more in depth. Then they go and collect data through experiments, observations, or surveys. With all of the data in hand, they analyze it to draw out conclusions.

classified in terms of how they were derived:

**Inductive hypothesis - a generalization based on observation**

**Deductive Hypotheses on pre-existing theory to start with**

**FORMING/DEVELOPING HYPOTHESIS**

Forming the hypotheses which will be tested, is one of the steps in the planning the research study

A hypothesis is formulated once,

The problem/point of proving (or disproving) has been identified and

The literature study has been conducted for the same (The researcher is totally aware of the theoretical and empirical background of concerned topic)

The Initial Idea: is the starting point

Often vague or general, it requires refining before research hypotheses can be generated

**Refinement of the initial idea is based on**

(1) A search of relevant research literature

(2) Initial observations made regarding the topic of study

Then initial idea is narrowed into a statement of the problem

In simple words, Ideas lead to

observations

library research

Statement of problem

Problem statements will become research hypotheses

**STEPS IN FORMULATING HYPOTHESIS / REFINING HYPOTHESIS**

**Identify area of interest to be researched**

Exclusive breast feeding and pneumonia

**Identify a research question – more narrow and specific :**

Does exclusive breast feeding reduces occurrence of pneumonia ?”

**Define the variables**

Pneumonia in infancy, community acquired pneumonia

**Formulate the hypothesis by making it a conditional statement**

Exclusively breast feeding reduces the occurrence of community acquired pneumonia in infancy

**Refine it by writing a formalized hypothesis like**

"If exclusive breast feeding reduces occurrence of CAP the exclusively breast fed babies has a lesser chance to develop pneumonia in infancy”

This type of "if-then" hypothesis is considered the most useful.

**Verify that a treatment or exposure is included in the experiment**– exclusive breast feeding

**Prepare for an outcome measure**

Rate of exclusively breast fed babies developing pneumonia

**Understand your control group**

Non exclusive breast fed babies

Remember: -Hypothesis can be adjusted/refined/changed as more information is gathered but before the actual examination/experiment is carried out

ABOUT AUTHORDr Jijo Jose is DCH and is currently pursuing secondary DNB from Aster Medcity, Kochi, Kerala |

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