HYPOTHESISHYPOTHESIS

Hypothesis Hypothesis

A tentative explanation for an A tentative explanation for an observation, phenomenon, or scientific observation, phenomenon, or scientific problem that can be tested by further problem that can be tested by further

investigation. A hypothesis describes in investigation. A hypothesis describes in concrete terms, in the form of a concrete terms, in the form of a

statement, what you expect willstatement, what you expect will happen happen in your study.in your study.

HYPOTHESISHYPOTHESIS It is a tentative prediction or explanation of It is a tentative prediction or explanation of

two or more variables two or more variables The hypothesis is the most important mental The hypothesis is the most important mental

tool the research has. tool the research has. It is important integral component of modern It is important integral component of modern

scientific research scientific research

PURPOSE OF HYPOTHESIS PURPOSE OF HYPOTHESIS It provides bridge between theory and reality and in It provides bridge between theory and reality and in

this sense unifying of two domainsthis sense unifying of two domains It provides powerful tool, for the advancement of It provides powerful tool, for the advancement of

knowledge since they enable the researcher to knowledge since they enable the researcher to objectively enter new areas of discovery objectively enter new areas of discovery

It provides direction for any research Endeavour by It provides direction for any research Endeavour by tentatively identifying the anticipated outcome. tentatively identifying the anticipated outcome.

It is guide to the thinking process and the process of It is guide to the thinking process and the process of discovery discovery

It serves as a framework for drawing conclusions It serves as a framework for drawing conclusions

Characteristics of HypothesisCharacteristics of Hypothesis It should be clear and precise It should be clear and precise It should be capable of being tested It should be capable of being tested It should state relationship between variables It should state relationship between variables It should be limited in scope and must be specific It should be limited in scope and must be specific It should be understandable It should be understandable It should be consistent with most known factsIt should be consistent with most known facts It should be test with amenable timeIt should be test with amenable time It should be comprises needed explanations It should be comprises needed explanations

Advantages Advantages

Hypothesis builds researches confidence in his Hypothesis builds researches confidence in his resultsresults

Sound hypothesis gives direction to the Sound hypothesis gives direction to the inquiry inquiry

A good hypothesis enriches theory A good hypothesis enriches theory

PROCESS OF HYPOTHESIS TESTINGPROCESS OF HYPOTHESIS TESTING

Stating the hypothesisStating the hypothesis Determining appropriate test statisticDetermining appropriate test statistic The significance levelThe significance level Decisional ruleDecisional rule Data collection and calculation performanceData collection and calculation performance Decision on Null hypothesisDecision on Null hypothesis Two tailed and one tailed testsTwo tailed and one tailed tests

PROCEDURE OF TESTING HYPOTHESISPROCEDURE OF TESTING HYPOTHESIS

Setting up of hypothesisSetting up of hypothesis Selecting level of significanceSelecting level of significance Determining sampling distributionDetermining sampling distribution Selecting sample and valueSelecting sample and value Performance computationPerformance computation Statistical decisionStatistical decision

Following aspects should be kept in mind when Following aspects should be kept in mind when formulating a hypothesisformulating a hypothesis::

Hypotheses can only be formulated after the researcher has gained Hypotheses can only be formulated after the researcher has gained enough knowledge regarding the nature, extent and intensity of the enough knowledge regarding the nature, extent and intensity of the problem. problem.

Hypotheses should figure throughout the research process in order Hypotheses should figure throughout the research process in order to give structure to the research. to give structure to the research.

Hypotheses are tentative statements/solutions or explanations of the Hypotheses are tentative statements/solutions or explanations of the formulated problem. Care should be taken not to over-simplify and formulated problem. Care should be taken not to over-simplify and generalize the generalize the formulationformulation of hypotheses. of hypotheses.

The research problem does not have to consist of one The research problem does not have to consist of one hypothesishypothesis only. The type of problem area investigated, the extent which only. The type of problem area investigated, the extent which encircles the research field are the determinating factors on how encircles the research field are the determinating factors on how many hypotheses will be included in the research proposal. many hypotheses will be included in the research proposal.

Criteria for the formulation of a hypothesisCriteria for the formulation of a hypothesisfollowing criteria are of importance in formulating following criteria are of importance in formulating

hypotheses. A hypotheses. A hypothesishypothesis should: should:

stand a test; stand a test; be expressed in clear language; be expressed in clear language; be in accordance with the general theme of other be in accordance with the general theme of other

hypotheses statements in the same field of study, and hypotheses statements in the same field of study, and should be regarded as valid; should be regarded as valid;

be. coordinated with the theory of science; be. coordinated with the theory of science; be a tentative answer to the formulated problem; be a tentative answer to the formulated problem; be logical and simplistic; be logical and simplistic; consider available research techniques (to be able to consider available research techniques (to be able to

analyze and interpret the results); analyze and interpret the results); be specific; and be specific; and

Steps inSteps in FormulatingFormulating a Hypothesisa Hypothesis

1.Decide what you want to explain: choose a 1.Decide what you want to explain: choose a dependent variable dependent variable

2. Choose independent variables that also show 2. Choose independent variables that also show variation variation

3. Think of multiple causes of the dependent 3. Think of multiple causes of the dependent variablevariable

4. Consider alternative measures of both the 4. Consider alternative measures of both the dependent and independent variablesdependent and independent variables. .

VARIABLES AND ATTRIBUTESVARIABLES AND ATTRIBUTES

Variable Variable – – Any entity that can take on different values. Anything that Any entity that can take on different values. Anything that

can be assigned a value.can be assigned a value.

Age can change. Nationality can differ. Age can change. Nationality can differ.

Variables are not always ‘quantitative’ or numerical. Variables are not always ‘quantitative’ or numerical.

Attribute –Attribute –a specific value on a variable a specific value on a variable

The variable The variable sexsex or or gendergender has two attributes: has two attributes: male male and and femalefemale. .

Or,Or,

The variable The variable agreementagreement might be defined as having might be defined as having five attributes:five attributes:

1=strongly agree1=strongly agree 2=disagree2=disagree 3=neutral3=neutral 4=agree4=agree 5=strongly agree5=strongly agree

TYPES of VARIABLESTYPES of VARIABLES

Independent VariableIndependent Variable Dependent VariableDependent Variable ExampleExampleResearch question – “How could extended use of the Internet Research question – “How could extended use of the Internet

negatively affect college students’ academic performance?”negatively affect college students’ academic performance?”  Extended use of the Internet negatively affects most college Extended use of the Internet negatively affects most college

students’ academic performancestudents’ academic performance

  Independent variable = internet use Independent variable = internet use attributes: high, moderate, low, noneattributes: high, moderate, low, none

  Dependent variable = PerformanceDependent variable = PerformanceAttributes: Good, average, BadAttributes: Good, average, Bad

Different forms of HypothesisDifferent forms of Hypothesis

A. A. Non Directional HypothesisNon Directional HypothesisAll examples of associated difference, sometimes calledAll examples of associated difference, sometimes called

non directional hypothesesnon directional hypotheses

B. Directional HypothesisB. Directional Hypothesis1. With magnitude1. With magnitude2. Without magnitude2. Without magnitude

TYPES OF HYPOTHESISTYPES OF HYPOTHESIS

The prediction is that variables A and B are The prediction is that variables A and B are related. related.

The only other possible outcome is that variables A The only other possible outcome is that variables A and B are and B are notnot rela relatedted

A.A.NULL HYPOTHESISNULL HYPOTHESIS

B. ALTERNATIVE HYPOTHESISB. ALTERNATIVE HYPOTHESIS

The Null HypothesisThe Null Hypothesis In In statistics, a , a null hypothesisnull hypothesis set up to be nullified set up to be nullified

or refutedor refuted which states that "there is no phenomenon". It is a which states that "there is no phenomenon". It is a

hypothesis that is presumed true until statistical that is presumed true until statistical evidence in the form of a in the form of a hypothesishypothesis test indicates test indicates otherwiseotherwise

HH0:μ1 = μ2 0:μ1 = μ2 where:where:HH0 = the null 0 = the null hypothesis hypothesis μ1 = the mean of population 1, and μ1 = the mean of population 1, and μ2 = the mean of population 2. μ2 = the mean of population 2.

The Alternative HypothesisThe Alternative Hypothesis

The alternative The alternative hypothesishypothesis is simply the question is simply the question you are asking you are asking

Denoted by HA or H1Denoted by HA or H1

Just opposite to Null HypothesisJust opposite to Null Hypothesis

H1: μ1 = μ2 H1: μ1 = μ2

TWO TAILED V/s ONE TAILED TESTTWO TAILED V/s ONE TAILED TEST

EXAMPLEEXAMPLEyou are investigating the effects of a new employee training you are investigating the effects of a new employee training program and that you believe one of the outcomes will be that program and that you believe one of the outcomes will be that there will be there will be lessless employee absenteeism. Your two hypotheses employee absenteeism. Your two hypotheses might be stated something like this: might be stated something like this:

The The null hypothesisnull hypothesis for this study is: for this study is: HO:HO: As a result of the XYZ company employee training As a result of the XYZ company employee training

program, there will either be no significant difference in program, there will either be no significant difference in employee absenteeism or there will be a significant employee absenteeism or there will be a significant increaseincrease..

which is tested against the which is tested against the alternative hypothesisalternative hypothesis:: HAHA: As a result of the XYZ company employee training : As a result of the XYZ company employee training

program, there will be a significant program, there will be a significant decrease decrease in employee in employee absenteeism.absenteeism.

ONE TAILED TESTONE TAILED TEST

TWO TAILED TESTTWO TAILED TEST

Type I errorType I error A A type I errortype I error, also known as an , also known as an error of the error of the

first kindfirst kind, is the wrong decision that is made , is the wrong decision that is made when a test rejects a true null hypothesis(when a test rejects a true null hypothesis(HH00))

Type II errorType II error A A type II errortype II error, also known as an , also known as an error of error of

the second kindthe second kind, is the wrong decision that is , is the wrong decision that is made when a test accepts a false null made when a test accepts a false null hypothesishypothesis