2. Hypoth. & R. Ques.pdf hypotheseis lecture

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2. 2

3. ❖Hypothesis:
✓Ahypothesisisadeclarativesentencethatpredictstheresultsof
aresearchstudybasedonexistingscientificknowledgeand
statedassumptions.
✓Itisapredictionthatanswerstheresearchquestion.
✓Itspecifiesarelationshipbetweentwoormorevariables.
▪E.g.Patientswhoreceivemedicationcounselingwillhavegreater
adherencetothemedicationregimen.
▪Variables:medicationcounselingandadherence.
✓Itinvolvesapredictionthataprogramoratreatmentwillcause
orotherwiseberelatedtoaspecifiedoutcome.
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❖Types of Hypothesis:
1.Directional hypothesis Vs Non directional hypothesis
2.Research hypothesis Vs Null hypothesis
3.Simple hypothesis Vs Complex hypothesis
▪Directionalhypothesis:Isone
thatspecifiesnotonlytheexistence
buttheexpecteddirectionofthe
relationshipbetweenvariables.
▪E.g.Highertheanterioroverjet
higherthechancesofanteriorteeth
fracture.
▪Thehypothesisisdirectional
becausethereisanexplicit
predictionthatthereisahigh
chanceofanteriorteethfracturein
peoplewithhigheranterioroverjet.
▪Nondirectionalhypothesisdoes
notstipulatethedirectionofthe
relationship.
▪E.g.Thereisanassociation
betweenthedegreeofanterior
overjetandanteriorteethfractures.
▪Thehypothesispredictsthat
anterioroverjetandanteriorteeth
fracturearerelatedbuttheydonot
stipulatewhethertheresearcher
thinksthatanterioroverjetisrelated
toincreasedordecreasedfracture
chances.

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❖Types of Hypothesis:
▪Researchhypothesis:
(alsoreferredtoassubstantive
orscientifichypothesis):Are
statementsofactualexpected
relationshipsbetweenvariables
andwhichindicateresearchers
trueexpectations.
➢E.g.Thereisarelationship
betweendailyintakeofrefined
sugarsandDMFTscorein
children.
▪Nullhypothesis:
(statisticalhypothesis)Itstates
thatthereisnorelationship
betweentheindependent
variablesanddependent
variables.
➢E.g.Thereisnorelationship
betweendailyintakeofrefined
sugarsandDMFTscorein
children.

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❖Types of Hypothesis:
▪Simplehypothesis:
Ahypothesiscanpredicttherelationshipbetweenasingle
independentvariableandasingledependentvariable.
▪E.g.Thelowerthelevelofhemoglobinthehigheristheriskof
infection.
▪Complexhypothesis:
Itcanpredictarelationshipbetweentwoormoreindependent
variablesortwoormoredependentvariables.
▪E.g.ThereisadifferenceintheeffectofDuraphatand
Fluorprotectorvarnishesonthedentalcariesincidence.

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❖Research Questionnaire:
➢Aquestionnaireisaresearch
instrumentthatconsistsof
asetofquestionsorother
typesofpromptsthataimsto
collectinformationfromaparticipantsorrespondents.
➢Aresearchquestionnaireistypicallyamixofclose-ended
questionsandopen-endedquestions.
✓Developingagoodresearchquestionnaireisthemostimportant
partoftheresearchprocess.
✓Aresearchprojectcanfailiftheobjectivesandhypothesisare
poorlyfocusedandunderdeveloped.
✓Aclearandorganizedstudydesignleadstosuccessfulresults.

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❖Research Questionnaire:
1.Awell-designedquestionnaireshouldmeet
theresearchobjectives.
2.Itshouldobtainthemostcomplete,
unbiasedandaccurateinformationpossible.
3.well-designedquestionnaireshouldmakeit
easyforrespondentstogivethenecessary
informationandfortheinterviewertorecord
theanswer,anditshouldbearrangedsothat
soundanalysisandinterpretationare
possible.
4.Itwouldkeeptheinterviewbriefandtothe
pointandbesoarrangedthatthe
respondent(s)remaininterestedthroughout
theinterview.
•Prescribedwordingandorderof
questions,toensurethateachrespondent
receivesthesamestimuli.
•Prescribeddefinitionsorexplanationsfor
eachquestion,toensureinterviewershandle
questionsconsistentlyandcananswer
respondents'requestsforclarificationifthey
occur.
•Prescribedresponseformat,toenable
rapidcompletionofthequestionnaireduring
theinterviewingprocess.

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❖Research Questionnaire:
▪Types of Questionnaire :
✓Anopen-endedquestionis
atypeofresearchquestion
thatdoesnotrestrict
respondentstoasetof
predeterminedanswers.
✓Usedwhenyouwantto
collectqualitativeresponses
foryourresearch.
✓Ithelpsyoutogather
detailedinformationfrom
respondents.
✓Itisverydifficultto
statisticallyinterpretthe
datacollectedviaopen-
endedquestions.This
makes open-ended
questionshighlyunsuitable
forquantitativedata
collection.
✓closed-endedquestions(as
thenamesuggest)enumerate
theoptionsforparticipantsto
selectfrom.
✓Itcomeswithpre-selected
answeroptionsandrequiresthe
respondenttochooseoneofthe
optionslikeYes/No,True/False,
andthelikes.
✓bestusedinquantitative
researchbecausetheyallow
youtocollectstatistical
informationfromrespondents.
✓Close-endedquestionsare
easyandquicktoanswered,
andcheapertocollateand
analyzethedata.
Thisdynamicpresentationusesthe
sameratingscalesandmultiple-choice
questionsbutthequestionorderand
choiceschangeusingadaptivelogic
(numericalalgorithmsprogrammedin
thesoftware).
Anunmoderatedusabilitytestcan
beviewedasaspecialtypeof
electronicsurveywithtask-based
questions.
IRT : Item Response Theory

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1. Decide the information required.
2. Define the target respondents.
3. Choose the method(s) of reaching your target respondents.
4. Decide on question content.
5. Develop the question wording.
6. Put questions into a meaningful order and format.
7. Check the length of the questionnaire.
8. Pre-test the questionnaire.
9. Develop the final survey form.
▪Preliminary decisions in questionnaire design:
There are nine steps involved in the development of a questionnaire:
❖Research Questionnaire:

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❖Research Questionnaire:
▪ criteria for a good research question :
Feasible:
•Adequatenumberofsubjects
•Adequatetechnicalexpertise
•Affordableintimeandmoney
•Manageableinscope
Interesting:
•Gettingtheanswerintriguesinvestigator,peersandcommunity.
Novel:
•Confirms,refutesorextendspreviousfindings.
Ethical:
•Amenabletoastudythatinstitutionalreviewboardwillapprove.
Relevant:
•Toscientificknowledge
•Toclinicalandhealthpolicy
•Tofutureresearch
▪What are the best medication
used for toothache?
▪Is this a good question?

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❖Research Questionnaire:
❑Format to use in the development of a specific research question
➢Considerthepopulation()ofinterest.
➢Theintervention()beingstudied.
➢Thecomparison()group(ortowhatistheinterventionbeing
compared).
➢Theoutcomeofinterest().
format :
▪Anadultpatientyoungerthan35yearsold
cametodentalclinicwithacuteperiapicalpain
(<2days)inlower2
nd
leftpremolar,doesthe
RCTreducetheriskofrecurrenceofpainwithin
oneyearcomparewithApicectomy?
▪Isthisagoodquestion?

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❖Research Questionnaire:

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❖Research Questionnaire:

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❖Research Questionnaire:
➢Considerationstobekeptinmindwhileconductingresearch:
✓Inanyresearchonhumanbeings,eachsubjectmustbe
adequatelyinformedoftheaim,methods,anticipatedbenefitsand
potentialhazardsofthestudyandthediscomfortitmayentail.
✓Whenobtaininginformedconsent,weshouldbecautiousifthe
subjecthasadependentrelationshiptous.Nopressureorthreat
shouldbeexercised.
✓Incaseoflegalincompetenceinformedconsentshouldbe
obtainedfromthelegalguardianinaccordancewiththeexisting
legislation.
✓Subjectshouldbeinformedthattheyarefreetoabstainorto
withdrawfromparticipationatanytime.