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Chapter13-ExperimentsandObservationalStudies
Name___________________________________
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Determinewhetherthereportdescribesaprospectiveobservationalstudy,aretrospectiveobservationalstudy,oranexperiment.
1)
Aneducationalresearcherusedschoolrecordstodeterminethat,inoneschooldistrict,84%ofchildrenlivingintwo-parenthomesgraduatedhighschoolwhile75%ofchildrenlivinginsingle-parenthomesgraduatedhighschool.
A) ExperimentB) RetrospectiveobservationalstudyC)
Prospectiveobservationalstudy
1)
2)
Inagroupof500menandwomen,thosewhosmokeddidworseontestsofreactiontimethanthosewhodidnotsmoke.
A) ExperimentB) RetrospectiveobservationalstudyC)
Prospectiveobservationalstudy
2)
3)
780patientssufferingfromhighbloodpressurewererandomlyassignedtooneofthreegroups.Overafour-monthperiod,thefirstgroupreceivedanexperimentaldrug,thesecondgroupreceivedaplacebo,andthethirdgroupreceivednotreatment.Thediastolicbloodpressureofeachparticipantwasmeasuredatthebeginningandattheendoftheperiodandthechangeinbloodpressurewasrecorded.Thebiggestdecreaseinbloodpressurewasforthosewhoreceivedthedrug.
A) ProspectiveobservationalstudyB) ExperimentC)
Retrospectiveobservationalstudy
3)
4)
Researchersreportedthatunmarriedmenaremorelikelytosufferfromclinicaldepressionthanmarriedmen.Thesefindingswerebasedonthemarriagehistoriesof700mensufferingfromdepressionand600mennotsufferingfromdepression.
A) ProspectiveobservationalstudyB) ExperimentC)
Retrospectiveobservationalstudy
4)
5)
400patientssufferingfromchronicbackpainwererandomlyassignedtooneoftwogroups.Overafour-monthperiod,thefirstgroupreceivedacupuncturetreatmentsandthesecondgroupreceivedaplacebo.Patientswhoreceivedacupuncturetreatmentsimprovedmorethanthosewhoreceivedtheplacebo.
A) RetrospectiveobservationalstudyB)
ProspectiveobservationalstudyC) Experiment
5)
6)
Amongagroupofmarriedwomenwhoweretrackedfortenyears,thosewhoworkedfulltimeweremorelikelytodivorcethanthosewhodidnotworkfulltime.
A) RetrospectiveobservationalstudyB)
ProspectiveobservationalstudyC) Experiment
6)
1
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7)
Aresearcherwishedtoassesstheimportanceofexerciseinweight-lossprograms.412people,allconsideredtobeatleast20poundsoverweight,wererandomlyassignedtooneoftwogroups.Overatwo-monthperiod,thefirstgroupfollowedaparticulardietbutwereinstructedtoperformnoexerciseotherthanwalking.Thesecondgroupfollowedthesamedietbutalsoperformedaerobicexerciseforonehoureachday.Attheendofthetwomonths,theweightlossofeachparticipantwasrecorded.Theaverageweightlossforthesecondgroupwasgreaterthantheaverageweightlossforthefirstgroup.
A) RetrospectiveobservationalstudyB) ExperimentC)
Prospectiveobservationalstudy
7)
8)
Anexaminationofthemedicalrecordsof10,000womenshowedthatthosewhowereshortandfairskinnedhadahigherriskofosteoperosis.
A) RetrospectiveobservationalstudyB)
ProspectiveobservationalstudyC) Experiment
8)
9)
Aneducationresearcherwasinterestedinexaminingtheeffectoftheteachingmethodandtheeffectoftheteacheronstudentsscoresonareadingtest.Supposetherearefourdifferentteachers(Juliana,Felix,Sonia,andHelen)andthreedifferentteachingmethods(A,B,andC).Studentswererandomlyassignedtoateachingmethodandteacher.ThosewhostudiedwthSoniausingmethodBachievedthehighestscores.
A) ProspectiveobservationalstudyB)
RetrospectiveobservationalstudyC) Experiment
9)
10)
Amongagroupofmenwhoweretrackedfortenyears,thosewhohadscoredover130onintelligencetestsweremorelikelytosufferseveredepressionthanthosewhohadscoredbelow130onintelligencetests.
A) ExperimentB) RetrospectiveobservationalstudyC)
Prospectiveobservationalstudy
10)
Anobservationalstudyisdescribed.Identifythespecifiedelement.11)
Aneducationalresearcherusedschoolrecordstodeterminethatintheyear2000inoneschool
district,84%ofchildrenlivingintwo-parenthomesgraduatedhighschoolwhile75%ofchildrenlivinginsingle-parenthomesgraduatedhighschool.Determinetheparameterofinterest.
A) SchooldistrictB)
Percentageofchildrenlivingintwo-parenthomesC)
YearofhighschoolgraduationD) HighschoolgraduationrateE)
Typeofhome(singleortwo-parent)
11)
12)
Inagroupof500women,thosewhosmokedmoderatelydidworseontestsofreactiontimethanthosewhodidnotsmoke.Identifythesubjectsstudied.
A) WomenB) WomenwhosmokemoderatelyC)
WomenwhosmokemoderatelyandwomenwhodonotsmokeD) WomenwhodonotsmokeE)
Adultswhosmokemoderatelyandadultswhodonotsmoke
12)
2
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13)
Inagroupof500women,thosewhosmokedmoderatelydidworseontestsofreactiontimethanthosewhodidnotsmoke.Determinethenatureandscopeoftheconclusionthestudycanreach.
A)
Smokingmoderatelycausespeopletodoworseontestsofreactiontime.B)
Sincethereisnorandomassignment,thereisnowaytoknowthatsmokingcausessubjects
todoworseontestsofreactiontime;theremayhavebeenconfoundingvariables.C)
Sincethereisnorandomassignment,thereisnowaytoknowthatsmokingcausessubjects
todoworseontestsofreactiontime;theremayhavebeenlurkingvariables.D)
Smokingmoderatelycauseswomentodoworseontestsofreactiontime.E)
Sincethestudyinvolvedonlywomen,thereisnowaytoknowthatsmokingcausespeople
todoworseontestsofreactiontime.
13)
14)
Researchersreportedthatunmarriedmenaremorelikelytosufferfromclinicaldepressionthanmarriedmen.Thesefindingswerebasedonthemarriagehistoriesof700Amercanmensufferingfromdepressionand600Americanmennotsufferingfromdepression.Determinethenatureandscopeoftheconclusionthestudycanreach.
A)
ForAmericanmen,gettingmarriedwillresultinadecreasedriskofdepression.B)
Formen,gettingmarriedwillresultinadecreasedriskofdepression.C)
Sincethereisnorandomassignment,thereisnowaytoknowthatbeingunmarriedincreases
theriskofdepression;theremayhavebeenlurkingvariables.D)
Sincethestudyinvolvedonlymen,thereisnowaytoknowthatbeingunmarriedincreases
theriskofdepression.E)
Sincethereisnorandomassignment,thereisnowaytoknowthatbeingunmarriedincreases
theriskofdepression;theremayhavebeenconfoundingvariables.
14)
15)
Amongagroupofmarriedwomenwhoweretrackedfortenyears,thosewhoworkedfulltimeweremorelikelytodivorcethanthosewhodidnotworkfulltime.Identifythesubjectsstudied.
A) DivorcedwomenwhoworkfulltimeB) DivorcedwomenC)
MarriedwomenworkingfulltimeornotD) MarriedwomenwhoworkfulltimeE)
Womenwhoworkfulltime
15)
16)
Anexaminationofthemedicalrecordsof10,000womenwhodiedbetween1990and2000showedthatthosewhohadtakensteroidshadahigherriskofosteoperosis.Identifythesubjectsstudied.
A) Womenwhodiedbetween1990and2000andwhohadtakensteroidsB)
WomenwhosufferedfromosteoperosisC) Womenwhodiedbetween1990and2000D)
WomenwhohadtakensteroidsE)
Womenwhodiedbetween1990and2000andwhohadsufferedfromosteoperosis
16)
17)
Anexaminationofthemedicalrecordsof10,000womenwhodiedbetween1990and2000showedthatthosewhohadtakensteroidshadahigherriskofosteoperosis.Identifytheparameterofinterest.
A) CauseofdeathB) GenderC) YearsofsteroidsuseD) YearofdeathE)
Riskofosteoperosis
17)
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18)
AmongagroupofCanadianmenwhoweretrackedfortenyears,thosewhohadscoredover130onintelligencetestsweremorelikelytosufferseveredepressionthanthosewhohadscoredbelow130onintelligencetests.Identifythesubjectsstudied.
A)
Canadianmenwhoscoredover130onintelligencetestsandwhoweresufferingfromdepression
B) CanadianmensufferingfromdepressionC)
Canadianmenwhodidnotscoreover130onintelligencetestsD) CanadianmenE)
Canadianmenwhoscoredover130onintelligencetests
18)
19)
AmongagroupofCanadianmenwhoweretrackedfortenyears,thosewhohadscoredover130onintelligencetestsweremorelikelytosufferseveredepressionthanthosewhohadscoredbelow130onintelligencetests.Identifytheparameterofinterest.
A) NationalityB) ScoreonintelligencetestC)
RiskofsufferingfromseveredepressionD) GenderE)
Numberofyearssincelastepisodeofseveredepression
19)
20)
AtSt.Lukeshospitalin1998,674womenwerediagnosedwithbreastcancer.Fiveyearslater,88%oftheCaucasianwomenand83%oftheAfricanAmericanwomenwerestillalive.Determinethenatureandscopeoftheconclusionthestudycanreach.
A)
Forwomenwithbreastcancer,beingCaucasiancausesanincreasedchanceofsurvivingfiveyears.
B)
ForCaucasianandAfricanAmericanwomenwithbreastcancer,attendingSt.Lukeshospitalcausesanincreasedchanceofsurvivingfiveyears.
C)
Sincethereisnorandomassignment,thereisnowaytoknowthatbeingCaucasiancauseswomenwithbreastcanceranincreasedchanceofsurvivingfiveyears;theremayhavebeenlurkingvariables.
D)
SincethestudyislimitedtoCaucasianandAfricanAmericanwomen,noconclusioncanbereached.
E)
Sincethereisnorandomassignment,thereisnowaytoknowthatbeingCaucasiancauseswomenwithbreastcanceranincreasedchanceofsurvivingfiveyears;theremayhavebeenconfoundingvariables.
20)
Adesignedexperimentisdescribed.Identifythespecifiedelement.21)
Inaclinicaltrial,780participantssufferingfromhighbloodpressurewererandomlyassignedto
oneofthreegroups.Overaone-monthperiod,thefirstgroupreceivedalowdosageofanexperimentaldrug,thesecondgroupreceivedahighdosageofthedrug,andthethirdgroupreceivedaplacebo.Thediastolicbloodpressureofeachparticipantwasmeasuredatthebeginningandattheendoftheperiodandthechangeinbloodpressurewasrecorded.Thebiggestdecreaseinbloodpressurewasforthosewhoreceivedthelowdosageofthedrug.Identifytheresponsevariablemeasured.
A) Thetreatmentreceived(placebo,lowdosage,highdosage)B)
Theone-monthperiodC) TheparticipantsintheexperimentD)
ChangeindiastolicbloodpressureE) Thedosageofthedrug
21)
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22)
780mensufferingfromhighbloodpressurewererandomlyassignedtooneofthreegroups.Overafour-monthperiod,thefirstgroupreceivedalowdosageofanexperimentaldrug,thesecondgroupreceivedahighdosageofthedrug,andthethirdgroupreceivedaplacebo.Thebiggestdecreaseinbloodpressurewasforthosewhoreceivedthelowdosageofthedrug.Identifythesubjectsstudied.
A) MensufferingfromhighbloodpressureB)
AdultssufferingfromhighbloodpressureC)
ChangeindiastolicbloodpressureD)
Thetreatmentreceived(placebo,lowdosage,highdosage)E)
Thedosageofthedrug
22)
23)
Aneducationresearcherwasinterestedinexaminingtheeffectoftheteachingmethodandtheteacheronthereadinglevelofstudentswithlearningdisabilities.257studentswithlearningdisabilitiesparticipatedinanexperiment.Therearefourdifferentteachers(Juliana,Felix,Sonia,andHelen)andthreedifferentteachingmethods(A,B,andC).Studentsarerandomlyassignedtoateachingmethodandateacher.ThosewhostudiedwithSoniausingmethodBachievedthehighestscoresonareadingtest.Identifythesubjectsstudied.
A) ScoreonreadingtestB) StudentswithlearningdisabilitiesC)
StudentswhostudiedwithSoniausingmethodBD) TeachingmethodE)
Teacher
23)
24)
Inaclinicaltrial,780participantssufferingfromhighbloodpressurewererandomlyassignedtooneofthreegroups.Overaone-monthperiod,thefirstgroupreceivedalowdosageofanexperimentaldrug,thesecondgroupreceivedahighdosageofthedrug,andthethirdgroupreceivedaplacebo.Thediastolicbloodpressureofeachparticipantwasmeasuredatthebeginningandattheendoftheperiodandthechangeinbloodpressurewasrecorded.Identifythelevelsofthefactor.
A) Theone-monthperiodB) Placebo,lowdosage,highdosageC)
TheexperimentaldrugD) Highbloodpressure,lowbloodpressureE)
Diastolicbloodpressureatthestart,diastolicbloodpressureattheend
24)
25)
Aneducationresearcherwasinterestedinexaminingtheeffectoftheteachingmethodandtheeffectoftheparticularteacheronstudentsscoresonareadingtest.Inastudy,therearefourdifferentteachers(Juliana,Felix,Sonia,andHelen)andthreedifferentteachingmethods(A,B,andC).Thenumberofstudentsparticipatinginthestudyis258.Studentsarerandomlyassignedtoateachingmethodandteacher.ThosewhostudiedwthSoniausingmethodBachievedthehighestscores.Identifytheresponsevariablemeasured.
A) ScoreonreadingtestB) TeachingmethodC)
MethodA,methodB,methodCD) TeacherE) Theeducationresearcher
25)
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26)
Aneducationresearcherwasinterestedinexaminingtheeffectoftheteachingmethodandtheeffectoftheparticularteacheronstudentsscoresonareadingtest.Inastudy,therearefourdifferentteachers(Juliana,Felix,Sonia,andHelen)andthreedifferentteachingmethods(A,B,andC).Thenumberofstudentsparticipatinginthestudyis258.Studentsarerandomlyassignedtoateachingmethodandteacher.Afterafour-monthperiod,studentstakeareadingtestandaregivenascoreoutof10.Identifythelevelsofthefactorteachingmethod.
A) ScoreonreadingtestB) Juliana,Felix,Sonia,andHelenC)
TeachingmethodandteacherD) MethodA,methodB,methodCE)
1,2,3,4,5,6,7,8,9,10
26)
27)
780mensufferingfromhighbloodpressurewererandomlyassignedtooneoftwogroups.Overafour-monthperiod,thefirstgroupreceivedanexperimentaldrugandthesecondgroupreceivedaplacebo.Alargerdecreaseindiastolicbloodpressurewasobservedforthosewhoreceivedthedrug.Theexperimentwasdouble-blind.Determinethenatureandscopeoftheconclusionthestudycanreach.
A)
Sincethephysiciansevaluatingtheresultscouldhavebeenbiased,noconclusioncanbereached.
B)
Sincethereisnorandomassignment,thereisnowaytoknowthatthedrugcausedthedecreaseindiastolicbloodpressure;therecouldhavebeenconfoundingvariables.
C)
Formensufferingfromhighbloodpressure,thedrugappearstolowerdiastolicbloodpressure.
D)
Sincethetechniciansadministeringthetreatmentcouldhavebeenbiased,noconclusioncanbereached.
E)
Foradultssufferingfromhighbloodpressure,thedrugappearstolowerdiastolicbloodpressure.
27)
28)
Aresearcherwantstoexaminetheeffectoffertilizerandtheeffectofsunlightontheyieldoftomatoes.Shebought60tomatoplantsatalocalgardenstore.Sherandomlyassigned30tomatoplantstobeplantedonthesunnysideofthehilland30tobeplantedontheshadyside.Withineachgroupof30plants,sherandomlyassignedplantstooneofthreegroups.Thefirstgroupisgrownwithnofertilizer,thesecondgroupwithasmallamountoffertilizer,andthethirdgroupwithalargeamountoffertilizer.Alltomatoplantsareplantedatthesametimeandarealltreatedalike(intermsofhowmuchtheyarewatered,weededetc).Eachplantisgrowntomaturity.Thetotalweightoftomatoesobtainedfromeachplantisrecorded.Thepersonevaluatingtheresultsdoesnotknowwhichtomatoesreceivedfertilizerorwhichweregrownonthesunnyside.Withinbothgroups(thosegrownonthesunnysideandthosegrownontheshadyside)tomatoesgrownwithalargeamountoffertilizeryieldedthemosttomatoes.Determinethenatureandscopeoftheconclusiontheexperimentcanreach.
A)
Fortomatoesgrownonthesunnyside,yieldmaybeincreasedfortomatoesgrownwithalargeamountoffertilizer.
B)
Yieldmaybeincreasedfortomatoesgrownonthesunnysidewithalargeamountoffertilizer.
C)
Yieldmaybeincreasedfortomatoesgrownwithalargeamountoffertilizer.D)
Sincethepersonevaluatingtheresultscouldhavebeenbiased,noconclusioncanbereached.E)
Sincethetechniciantendingtotheplantscouldhavebeenbiased,noconclusioncanbe
reached.
28)
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29)
Aresearcherwantstoinvestigatetheeffectivenessofacholesterol-loweringmedication.The450participantsarefirstdividedintotwogroups-thosesufferingfromdiabetesandthosenotsufferingfromdiabetes.Withineachgrouptheparticipantsarerandomlyassignedtooneofthreegroups.Thefirstgroupwillreceivealowdoseofthemedication,thesecondgroupwllreceiveahighdoseofthemedication,andthethirdgroupwillreceiveaplacebo.Attheendofasix-monthperiod,eachpersonscholesterolwillbetestedandthechangeintheircholesterollevelwillberecorded.Theexperimentisdoubleblind.Withinthegroupsufferingfromdiabetes,thosetakingahighdoseofthemedicationshowedamarkeddecreaseintheircholesterollevel.Determinethenatureandscopeoftheconclusiontheexperimentcanreach.
A)
Sincethephysiciansevaluatingtheresultscouldhavebeenbiased,noconclusioncanbereached.
B) Ahighdoseofthemedicationmaydecreasecholesterollevels.C)
Sincethetechniciansadministeringthetreatmentcouldhavebeenbiased,noconclusioncan
bereached.D)
Forpeoplesufferingfromdiabetes,ahighdoseofthemedicationmaydecreasecholesterol
levels.E)
Peoplesufferingfromdiabetesmayexperienceadecreaseincholesterollevels.
29)
30)
780participantssufferingfromdepressionwererandomlyassignedtooneofthreegroups.Overafour-monthperiod,thefirstgroupreceivedalowdosageofanexperimentaldrug,thesecondgroupreceivedahighdosageofthedrug,andthethirdgroupreceivedaplacebo.Attheendoftheperiodeachparticipantratedtheirmoodonascaleof1-10.Identifythefactor(s)intheexperimentandthenumberoflevelsforeach.
A) Theexperimentaldrug(3levels),mood(10levels)B)
Placebo,lowdosage,highdosage(3levels)C)
Thedosageofthedrug(3levels)D) Theexperimentaldrug(3levels)E)
Mood(10levels)
30)
31)
780participantssufferingfromdepressionwererandomlyassignedtooneofthreegroups.Overafour-monthperiod,thefirstgroupreceivedalowdosageofanexperimentaldrug,thesecondgroupreceivedahighdosageofthedrug,andthethirdgroupreceivedaplacebo.Attheendoftheperiodeachparticipantratedtheirmoodonascaleof1-5.Identifythetreatments.
A) Theexperimentaldrug,moodB) Placebo,lowdosage,highdosageC)
ThedosageofthedrugD)
Moodlevel1,moodlevel2,moodlevel3,moodlevel4,moodlevel5E)
Theexperimentaldrug
31)
32)
Aneducationresearcherwasinterestedinexaminingtheeffectoftheteachingmethodandtheteacheronstudentsreadinglevels.257studentsparticipatedinanexperiment.Thereweretwodifferentteachers(JulianaandFelix)andthreedifferentteachingmethods(A,B,andC).Studentswererandomlyassignedtoateachingmethodandteacher.Attheendofthesemesterthestudentstookareadingtestonwhichtheyreceivedascoreoutof20.StudentswhostudiedwthFelixusingmethodBachievedthehighestscores.Identifythefactor(s)intheexperimentandthenumberoflevelsforeach.
A)
Teachingmethod(3levels),teacher(2levels),scoreonreadingtest(20levels)B)
JulianaandmethodA,JulianaandmethodB,JulianaandmethodC,FelixandmethodA,
FelixandmethodB,FelixandmethodC(6levels)C)
Teachingmethod(3levels)andteacher(2levels)D)
Scoreonreadingtest(20levels)E)
Theteacherandteachingmethodcombination(6levels)
32)
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33)
Aneducationresearcherwasinterestedinexaminingtheeffectoftheteachingmethodandtheteacheronstudentsreadinglevels.257studentsparticipatedinanexperiment.Thereweretwodifferentteachers(JulianaandFelix)andthreedifferentteachingmethods(A,B,andC).Studentswererandomlyassignedtoateachingmethodandteacher.Attheendofthesemesterthestudentstookareadingtestonwhichtheyreceivedascoreoutof4.StudentswhostudiedwthFelixusingmethodBachievedthehighestscores.Identifythenumberoftreatmentsandlistthem.
A) 24;Score1,Juliana,methodA,Score1,Juliana,methodB,
Score1,Juliana,methodC,Score2,Juliana,methodA,
Score2,Juliana,methodB,
Score2,Juliana,methodC,Score3,Juliana,methodA,
Score3,Juliana,methodB,
Score3,Juliana,methodC,Score4,Juliana,methodA,
Score4,Juliana,methodB,
Score4,Juliana,methodC,Score1,Felix,methodA,Score1,Felix,methodB,Score1,Felix,methodC,Score2,Felix,methodA,Score2,Felix,methodB,Score2,Felix,methodC,Score3,Felix,methodA,Score3,Felix,methodB,Score3,Felix,methodC,Score4,Felix,methodA,Score4,Felix,methodB,Score4,Felix,methodC
B) 3;MethodA,methodB,methodCC) 4;Score1,score2,score3,score4D)
6;JulianaandmethodA,JulianaandmethodB,JulianaandmethodC,FelixandmethodA,
FelixandmethodB,FelixandmethodCE) 2;Juliana,Felix
33)
34)
Aresearcherwantstoexaminetheeffectoffertilizerandtheeffectofsunlightontheyieldoftomatoes.Shebought60tomatoplantsatalocalgardenstore.Sherandomlyassigned30tomatoplantstobeplantedonthesunnysideofthehilland30tobeplantedontheshadyside.The30plantswhichareplantedontheshadysidearerandomlyassignedtooneofthreegroups.Thefirstgrouparegrownwithnofertilizer,thesecondgroupwithasmallamountoffertilizer,andthethirdgroupwithalargeamountoffertilizer.The30plantswhichareplantedonthesunnysidearelikewiserandomlyassignedtooneofthreegroups.Thefirstgrouparegrownwithnofertilizer,thesecondgroupwithasmallamountoffertilizerandthethirdgroupwithalargeamountoffertilizer.Alltomatoplantsareplantedatthesametimeandarealltreatedalike(intermsofhowmuchtheyarewatered,weededetc).Eachplantisgrowntomaturity.Thetotalweightoftomatoesobtainedfromeachplantisrecorded.Identifythefactor(s)andthenumberoflevelsforeach.
A) Fertilizer(3levels),location(2levels)B)
Nofertilizer,smallamountoffertilizer,largeamountoffertilizer(3levels)C)
Nofertilizerandsunny,smallamountoffertilizerandsunny,largeamountoffertilizerand
sunny,nofertilizerandshady,smallamountoffertilizerandshady,largeamountoffertilizerandshady(6levels)
D) Sunny,shady(2levels)E) Fertilizer(3levels),blockingvariable-
location(2levels)
34)
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35)
Aresearcherwantstoexaminetheeffectoffertilizerandtheeffectofsunlightontheyieldoftomatoes.Shebought60tomatoplantsatalocalgardenstore.Sherandomlyassigned30tomatoplantstobeplantedonthesunnysideofthehilland30tobeplantedontheshadyside.The30plantswhichareplantedontheshadysidearerandomlyassignedtooneofthreegroups.Thefirstgrouparegrownwithnofertilizer,thesecondgroupwithasmallamountoffertilizer,andthethirdgroupwithalargeamountoffertilizer.The30plantswhichareplantedonthesunnysidearelikewiserandomlyassignedtooneofthreegroups.Thefirstgrouparegrownwithnofertilizer,thesecondgroupwithasmallamountoffertilizerandthethirdgroupwithalargeamountoffertilizer.Alltomatoplantsareplantedatthesametimeandarealltreatedalike(intermsofhowmuchtheyarewatered,weededetc).Eachplantisgrowntomaturity.Thetotalweightoftomatoesobtainedfromeachplantisrecorded.Identifythetreatments.
A) Fertilizer,locationB)
Nofertilizer,smallamountoffertilizer,largeamountoffertilizerC)
Nofertilizerandsunny,smallamountoffertilizerandsunny,largeamountoffertilizerand
sunny,nofertilizerandshady,smallamountoffertilizerandshady,largeamountoffertilizerandshady
D) Fertilizer,blockingvariable-locationE) Sunny,shady
35)
36)
Aresearcherwantstoinvestigatewhetherdifferentformsofexercisecanbeusedtohelphyperactivechildren.Agroupof90childrenisdividedintotwogroupsaccordingtoage
-thoseaged9-12andthoseaged5-8.Withineachagegroupthechildrenarerandomlyassignedtooneofthreegroups.Thefirstgroupwilljustdotheirnormalexercise.Thesecondgroupwillbegivenanadditionalexerciseroutine(moderate).Thethirdgroupwillbegivenanadditionalexerciseroutine(strenuous).Attheendofafourmonthperiodparentswillbeaskedtoevaluatetheirchildrensprogress.Identifythefactor(s)andanyblockingvariablesandthenumberoflevelsforeach.
A) Blockingvariable:exercise(3levels),Factor:age(2levels)B)
Factor:exercise(3levels),Blockingvariable:age(2levels)C)
Factor:exercise(3levels),Factor:age(2levels)D)
Normalexerciseandage5-8,additionalexercise(moderate)andage5-8,additionalexercise
(strenuous)andage5-8,normalexerciseandage9-12,additionalexercise(moderate)andage9-12,additionalexercise(strenuous)andage9-12(6levels)
E)
Factor:Normalexercise,additionalexercise(moderate),additionalexercise(strenuous)(3levels)
36)
37)
Aresearcherwantstoinvestigatewhetherdifferentformsofexercisecanbeusedtohelphyperactivechildren.Agroupof90childrenisdividedintotwogroupsaccordingtoage
-thoseaged9-12andthoseaged5-8.Withineachagegroupthechildrenarerandomlyassignedtooneofthreegroups.Thefirstgroupwilljustdotheirnormalexercise.Thesecondgroupwillbegivenanadditionalexerciseroutine(moderate).Thethirdgroupwillbegivenanadditionalexerciseroutine(strenuous).Attheendofafourmonthperiodparentswillbeaskedtoevaluatetheirchildrensprogress.Identifythetreatments.
A) Exercise,blockingvariable-ageB)
Normalexercise,additionalexercise(moderate),additionalexercise(strenuous)C)
Normalexerciseandage5-8,additionalexercise(moderate)andage5-8,additionalexercise
(strenuous)andage5-8,normalexerciseandage9-12,additionalexercise(moderate)andage9-12,additionalexercise(strenuous)andage9-12
D) Age5-8,age9-12E) Exercise,age
37)
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38)
Aresearcherwantstoinvestigatetheeffectivenessofacholesterol-loweringmedication.The450participantsarefirstdividedintotwogroups-thosesufferingfromdiabetesandthosenotsufferingfromdiabetes.Withineachgrouptheparticipantsarerandomlyassignedtooneofthreegroups.Thefirstgroupwillreceivealowdoseofthemedication,thesecondgroupwllreceiveahighdoseofthemedication,andthethirdgroupwillreceiveaplacebo.Attheendofasix-monthperiod,eachpersonscholesterolwillbetestedandthechangeintheircholesterollevelwillberecorded.Identifythefactor(s)andanyblockingvariablesandthenumberoflevelsforeach.
A) Factor:Medication(3levels),Factor:diabetes(2levels)B)
Factor:Diabetes,nodiabetes(2levels)C)
Factor:Placeboanddiabetes,lowdoseofmedicationanddiabetes,highdoseofmedication
anddiabetes,placeboandnodiabetes,lowdoseofmedicationandnodiabetes,highdoseofmedicationandnodiabetes(6levels)
D)
Factor:Medication(3levels),Blockingvariable:diabetes(2levels)E)
Factor:Placebo,lowdoseofmedication,highdoseofmedication(3levels)
38)
39)
Aresearcherwantstoinvestigatetheeffectivenessofacholesterol-loweringmedication.The450participantsarefirstdividedintotwogroups-thosesufferingfromdiabetesandthosenotsufferingfromdiabetes.Withineachgrouptheparticipantsarerandomlyassignedtooneofthreegroups.Thefirstgroupwillreceivealowdoseofthemedication,thesecondgroupwllreceiveahighdoseofthemedication,andthethirdgroupwillreceiveaplacebo.Attheendofasix-monthperiod,eachpersonscholesterolwillbetestedandthechangeintheircholesterollevelwillberecorded.Identifythetreatments.
A) Medication(3levels),blockingvariable- diabetes(2levels)B)
Medication(3levels),changeincholesterolC)
Placebo,lowdoseofmedication,highdoseofmedication(3levels)D)
Placeboanddiabetes,lowdoseofmedicationanddiabetes,highdoseofmedicationand
diabetes,placeboandnodiabetes,lowdoseofmedicationandnodiabetes,highdoseofmedicationandnodiabetes(6levels)
E) Medication(3levels),diabetes(2levels)
39)
Describethedesignoftheexperiment(completelyrandomizedorblocked).40)
Inaclinicaltrial,780participantssufferingfromhighbloodpressurewererandomlyassignedto
oneofthreegroups.Overaone-monthperiod,thefirstgroupreceivedalowdosageofanexperimentaldrug,thesecondgroupreceivedahighdosageofthedrug,andthethirdgroupreceivedaplacebo.Thediastolicbloodpressureofeachparticipantwasmeasuredatthebeginningandattheendoftheperiodandthechangeinbloodpressurewasrecorded.Thebiggestdecreaseinbloodpressurewasforthosewhoreceivedthelowdosageofthedrug.
A)
Completelyrandomizedoveronefactor(experimentaldrug),blockedbydiastolicbloodpressure
B)
Completelyrandomizedovertwofactors(experimentaldrug,diastolicbloodpressure)C)
Completelyrandomizedoveronefactor(experimentaldrug)D)
Blockedbyexperimentaldrug,blockedbydiastolicbloodpressureE)
Completelyrandomizedoveronefactor(diastolicbloodpressure),blockedbyexperimental
drug
40)
10
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41)
Aneducationresearcherwasinterestedinexaminingtheeffectoftheteachingmethodandtheteacheronstudentsreadinglevels.257studentsparticipatedinanexperiment.Thereweretwodifferentteachers(JulianaandFelix)andthreedifferentteachingmethods(A,B,andC).Studentswererandomlyassignedtoateachingmethodandteacher.Attheendofthesemesterthestudentstookareadingtestonwhichtheyreceivedascoreoutof20.StudentswhostudiedwthFelixusingmethodBachievedthehighestscores.
A)
Completelyrandomizedoveronefactor(teachingmethod),blockedbyteacherB)
Completelyrandomizedovertwofactors(teachingmethodandteacher)C)
Completelyrandomizedoveronefactor(teachingmethod)D)
Completelyrandomizedoveronefactor(teacher),blockedbyteachingmethodE)
Blockedbyteacher,blockedbyteachingmethod
41)
42)
Aresearcherwantstoexaminetheeffectoffertilizerandtheeffectofsunlightontheyieldoftomatoes.Shebought60tomatoplantsatalocalgardenstore.Sherandomlyassigned30tomatoplantstobeplantedonthesunnysideofthehilland30tobeplantedontheshadyside.The30plantswhichareplantedontheshadysidearerandomlyassignedtooneofthreegroups.Thefirstgrouparegrownwithnofertilizer,thesecondgroupwithasmallamountoffertilizer,andthethirdgroupwithalargeamountoffertilizer.The30plantswhichareplantedonthesunnysidearelikewiserandomlyassignedtooneofthreegroups.Thefirstgrouparegrownwithnofertilizer,thesecondgroupwithasmallamountoffertilizer,andthethirdgroupwithalargeamountoffertilizer.Alltomatoplantsareplantedatthesametimeandarealltreatedalike(intermsofhowmuchtheyarewatered,weededetc).Eachplantisgrowntomaturity.Thetotalweightoftomatoesobtainedfromeachplantisrecorded.
A) Completelyrandomizedoveronefactor(fertilizer)B)
Completelyrandomizedoveronefactor(location),blockedbyfertilizerC)
Completelyrandomizedovertwofactors(fertilizerandlocation)D)
Blockedbyfertilizer,blockedbylocationE)
Completelyrandomizedoveronefactor(fertilizer),blockedbylocation
42)
43)
Aresearcherwantstoinvestigatewhetherdifferentformsofexercisecanbeusedtohelphyperactivechildren.Agroupof90childrenisdividedintotwogroupsaccordingtoage
-thoseaged9-12andthoseaged5-8.Withineachagegroupthechildrenarerandomlyassignedtooneofthreegroups.Thefirstgroupwilljustdotheirnormalexercise.Thesecondgroupwillbegivenanadditionalexerciseroutine(moderate).Thethirdgroupwillbegivenanadditionalexerciseroutine(strenuous).Attheendofafourmonthperiodparentswillbeaskedtoevaluatetheirchildrensprogress.
A) Completelyrandomizedoveronefactor(exercise),blockedbyageB)
Completelyrandomizedoveronefactor(exercise)C)
Completelyrandomizedoveronefactor(exercise),blockedbyageandlevelofhyperactivityD)
Completelyrandomizedovertwofactors(exerciseandage)E)
Completelyrandomizedoveronefactor(age),blockedbyexercise
43)
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44)
Aresearcherwantstoinvestigatetheeffectivenessofacholesterol-loweringmedication.The450participantsarefirstdividedintotwogroups-thosesufferingfromdiabetesandthosenotsufferingfromdiabetes.Withineachgrouptheparticipantsarerandomlyassignedtooneofthreegroups.Thefirstgroupwillreceivealowdoseofthemedication,thesecondgroupwllreceiveahighdoseofthemedication,andthethirdgroupwillreceiveaplacebo.Attheendofasix-monthperiod,eachpersonscholesterolwillbetestedandthechangeintheircholesterollevelwillberecorded.
A) Completelyrandomizedovertwofactors(medicationanddiabetes)B)
Completelyrandomizedovertwofactors(medicationanddiabetes),blockedbycholesterol
levelC)
Completelyrandomizedoveronefactor(medication),blockedbydiabetesD)
Completelyrandomizedoveronefactor(medication),blockedbydiabetesandcholesterol
levelE)
Completelyrandomizedoveronefactor(diabetes),blockedbymedication
44)
Determinewhethertheexperimentissingle-blind, double-blind,
orneither.45)
Aresearcherwantstoexaminetheeffectoffertilizerandtheeffectofsunlightontheyieldof
tomatoes.Shebought60tomatoplantsatalocalgardenstore.Sherandomlyassigned30tomatoplantstobeplantedonthesunnysideofthehilland30tobeplantedontheshadyside.Withineachgroupof30plants,sherandomlyassignedplantstooneofthreegroups.Thefirstgroupisgrownwithnofertilizer,thesecondgroupwithasmallamountoffertilizer,andthethirdgroupwithalargeamountoffertilizer.Alltomatoplantsareplantedatthesametimeandeachplantisgrowntomaturity.Thetotalweightoftomatoesobtainedfromeachplantisrecorded.Thepersonevaluatingtheresultsdoesnotknowwhichtomatoesreceivedfertilizerorwhichweregrownonthesunnyside.
A) Single-blind B) Double-blind C) Neither
45)
46)
Aneducationresearcherwasinterestedinexaminingtheeffectoftheteachingmethodandtheteacheronstudentsreadinglevels.257studentsparticipatedinanexperiment.Thereweretwodifferentteachers(JulianaandFelix)andthreedifferentteachingmethods(A,B,andC).Studentswererandomlyassignedtoateachingmethodandteacher.Attheendofthesemesterthestudentstookareadingtestonwhichtheyreceivedascoreoutof20.StudentswhostudiedwthFelixusingmethodBachievedthehighestscores.Thepersonevaluatingtheresultsdoesnotknowwhichteacherorteachingmethodthestudentswereassignedto.
A) Single-blind B) Double-blind C) Neither
46)
47)
Aresearcherwantstoinvestigatewhetherdifferentformsofexercisecanbeusedtohelphyperactivechildren.Agroupof90childrenisdividedintotwogroupsaccordingtoage
-thoseaged9-12andthoseaged5-8.Withineachagegroupthechildrenarerandomlyassignedtooneofthreegroups.Thefirstgroupwilljustdotheirnormalexercise.Thesecondgroupwillbegivenanadditionalexerciseroutine(moderate).Thethirdgroupwillbegivenanadditionalexerciseroutine(strenuous).Attheendofafourmonthperiodparentswillbeaskedtoevaluatetheirchildrensprogress.
A) Single-blind B) Double-blind C) Neither
47)
12
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48)
780mensufferingfromhighbloodpressurewererandomlyassignedtooneoftwogroups.Overafour-monthperiod,thefirstgroupreceivedanexperimentaldrugandthesecondgroupreceivedaplacebo.Alargerdecreaseindiastolicbloodpressurewasobservedforthosewhoreceivedthedrug.Thepatientsdidnotknowwhethertheywerereceivingthedrugortheplacebo.Neitherthetechniciansadministeringthetreatmentsnorthephysiciansevaluatingtheresultsknewwhichparticipantshadreceivedthedrugandwhichtheplacebo.
A) Single-blind B) Double-blind C) Neither
48)
49)
IstheAddisonWesleyAlgebraItextsuperiortothecurrentlyusedtext,inpromotinglearningofalgebra?EvaluatorsonlyareinformedthatGroupAwilltestfromthecurrenttextandGroupBwilltestfromAWtext.
A) Single-blind B) Double-blind C) Neither
49)
50)
IstheaspirinproducedbyWorldsBestPharmaceuticalCompanybetterthanthatofacompetitoratrelievingheadaches?200headachesuffersarechosenatrandom.MigranedTestingServiceadministerstheexperimentandprovidestheresultsevaluation.Threelevelsaremade:participantsreceivecontentsfromBottleA,BottleB,orBottleC.Otherthanthefactthatonebottlecontainsplaceboaspirin,nootherinformationisgiventothetestingserviceregardingthebottlescontents.
A) Single-blind B) Double-blind C) Neither
50)
51)
DoSlimquickshakesreduceweightloss?TestersprovideSlimquickshakesforparticipantsingroups1and5.Groups2,3,and4areprovidedwithStoutslowshakes.Resultsareevaluatedbythegroupidentifier,withnotreatmentinformationcommunicated.
A) Single-blind B) Double-blind C) Neither
51)
52)
Doesanewbrandofhandlotioncauseanallergicreactioninsomepeople?Participantsareallowedtojoinoneofthreestudies.Twoofthestudiesusewell-knownnamebrandlotionsandthethirdistheNEWlotion.Theresultsdocumentwillbepreparedbyanoteddermatologist,whoisinformedofthecompositionofeachgroup.
A) Single-blind B) Double-blind C) Neither
52)
53)
Doenergysnackbarsimproveafternoonalertness?100factoryworkerswereramdomlyassignedtotwogroups.Onegroupateenergysnackbarsatlunchandtheothergroupateplacebosnackbars.Attheafternoonbreak(approximately1-1/2hourafterlunch),asignificantincreaseinalertnesswasobserved.Lateranalysisoftheexperimentresultsshowed87%oftheparticipantsexhibitngincreasedalertnesswerefromthegroupwhichateenergysnackbars.
A) Single-blind B) Double-blind C) Neither
53)
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Answerthequestion.54)
Adouble-blindexperimentofanallergymedicationisbeingtestedon100participantsaccording
tothisdiagram:
IfGroup2receivesafulldoseofthemedication,whatshouldGroup1streatmentconsistof?A)
AplaceboB) A50%doseC) RandomizeddosesD) BlockeddosesE)
Stratifieddoses
54)
55)
Anewtypeofpainrelieverisadministeredto30consentingpost-operativepatientsinvarioushospitals.Althoughthepainrelieverhasalreadybeentestedforsafetyandeffectiveness,thisexperimentistoobserveandcategorizeanyside-effects.Becauseofmaturityandbodymass,itisdecidedtotesttheadultsseparatelyfromthechildren.
Thegroupingoftheadultsseparatefromthechildrenisanexampleofwhat?A)
ControllingB) MatchingC) ReductionofconfoundingfactorsD) BlockingE)
Stratifying
55)
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56)
TheAsianlonghornedbeetlekillstreesbyburrowingwithinthetrunkandbranchesanddisruptingthesapflow.Thisbeetlefavorshardwoodtrees,suchasmaple,elm,andash.Anewpesticidewillbebetestedinamajormetropolitancity.Astatisticiandesignsanexperimentfor200maturemapletreesandrandomlyassignshalfofthetreestoreceivethisnewpesticide,andtherestofthetreesreceiveacontroltreatment.
Isthereanyobviouswaytoimprovethisexperimenttoevaluatetheeffectivenessofthisnewpesticide?
A) Yes,stratifyingmustbeused.B)
No,basicvariationshavebeenaccountedfor.C) Yes,aplaceboismissing.D)
Yes,blockingmustbeused.E) Yes,matchingmustbeused.
56)
57)
Apharmaceuticalcompanywillbetestinganewone-dosagefitsallmedicationfortreatingdepression.Thepharmaceuticalcompanyhas100willingtestsubjectsthatwillundergoa30-day,double-blindexperiment.Theexperimentusesthefollowingdiagramasaguideforadministeringthemedicationatvariousdoses,from5%to125%.
Whatisthemostobviousfactormissingfromthisproposedexperiment?A)
A100%dosageB) Blockingmustbeused.C) AcontrolgroupD)
Stratifyingmustbeused.E)
Nothingismissing.Basicvariationshavebeenaccountedfor.
57)
15
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58)
Aclothingmanufactureriscuriousifcelebrityendorsementswillinfluenceacustomersdecisioninbuyingitsproducts.Thisclothingmanufacturerpremieresitslatestseriesofcommercialsprivatelytotwoseparategroupsofpotentialshoppers.Onegroupwillseeaseriesofcommercialswithoutcelebrities,andonegroupwillseeaseriesofcommercialswithcelebrities.Furthermore,themanufacturerdecidestosplitupthemaleshoppersfromthefemaleshoppers.
Groupingtheshopperstogetherbygenderisanexampleofwhat?A)
ReductionofconfoundingfactorsB) FactoringC) BlockingD)
StratifyingE) Matching
58)
Identifytheflaw(s)intheexperimentorstudydescribed.59)
AtSt.Lukeshospitalin1998,674womenwerediagnosedwithbreastcancer.Fiveyearslater,88%
oftheCaucasianwomenand83%oftheAfricanAmericanwomenwerestillalive.AresearcherconcludesthatbeingCaucasiancauseswomenwithbreastcanceranincreasedchanceofsurvivingfiveyears.Sincethereisnorandomassignmentandtheremayhavebeenlurkingvariables,thisconclusionisnotjustified.Whichofthefollowingarepossiblelurkingvariables?
I:IncomeII:NeighborhoodwherepatientlivesIII:QualityofhealthcareIV:DietV:Numberofyearssurvivingsincediagnosis
A) I,II,III,IVB) I,III,IVC) I,IVD) II,IVE) I,II,III,IV,V
59)
16
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60)
Researchersreportedthatformen,beingunmarriedincreasestheriskofdepression.Thesefindingswerebasedonthemedicalrecordsof400marriedmenand500unmarriedmen.Sincethereisnorandomassignment,thisconclusionisnotjustifiedbecausetheremaybelurkingvariables.Whichofthefollowingarepossiblelurkingvariables?
I:RateofdepressionII:IncomeIII:TypeofemploymentIV:AgeV:Gender
A) II,III,IV,VB) II,III,IVC) I,II,IIID) II,IVE) III,IV
60)
61)
Amedicalresearcherbelievesthatsupplementsofglucosaminecanhelptoreducethepainofarthritis.Shewouldliketotestthesupplementattwodifferentdosagelevels.Shedesignsanexperimentasfollowstotestherconjecture.Shewillobtainagroupofvolunteerswhosufferfromarthritis.Eachpatientsconditionwillbeevaluatedbyadoctoratthestartoftheexperiment.Volunteerswillberandomlyassignedtooneoftwogroups.Eachdayforthedurationoftheexperiment,patientsingroup1willreceivealowdoseofglucosamine,patientsingroup2willreceiveahigherdoseofglucosamine.Afterasuitableamountoftime(twomonths,forexample),thedoctorwillevaluateeachpatientsprogress.Basedontheamountofinflammationandthepatientsreportontheamountofpain,thedoctorwillgiveeachpatientanumericalscoretorepresenttheirimprovement.Theamountofimprovementforthetwogroupswouldthenbecompared.Shewillhavetheevaluatingdoctorandthetechniciansadministeringthesupplementsblindedtowhetherpatientsreceivealowdoseorhighdose.Identifythemostseriousflawinthisexperiment.
A)
Theexperiementisnotdoubleblind,doctorevaluatingtheprogressmaybebiased.B)
Volunteersshouldhavebeenselectedrandomly.C) Thereisnoblocking.D)
Therecouldbelurkingvariables.E) Thereisnoplacebogroup.
61)
17
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62)
Apharmaceuticalcompanyhasdevelopedamedicationwhichtheybelievewillhelptoreducethepainofarthritis.Theywouldliketotestthemedicationattwodifferentdosagelevels.Theydesignanexperimentasfollowstotestthemedication.Theywillobtainagroupofvolunteerswhosufferfromarthritis.Adoctorfromthepharmaceuticalcompanywillevaluateeachpatientsconditionatthestartoftheexperiment.Volunteerswillberandomlyassignedtooneofthreegroups.Eachdayforthedurationoftheexperiment,patientsingroup1willreceivealowdoseofthemedication,patientsingroup2willreceiveahigherdoseofthemedication,andpatientsingroup3willreceiveaplacebo.Afterasuitableamountoftime(twomonths,forexample),thesamedoctorwillevaluateeachpatientsprogress.Basedontheamountofinflammationandthepatientsreportontheamountofpain,thedoctorwillgiveeachpatientanumericalscoretorepresenttheirimprovement.Theamountofimprovementforthethreegroupswillthenbecompared.Theresearcherswillhavethetechniciansadministeringthemedicationblindedtowhetherpatientsreceivealowdose,ahighdose,oraplacebo.Identifythemostseriousflawinthisexperiment.
A)
Theexperimentisonlysingleblind.Thedoctorevaluatingthepatientsprogressisnotblindtowhichtreatmentpatientsreceived.
B) Therecouldbelurkingvariables.C)
Thevolunteersshouldhavebeenrandomlyselected.D) Thereisnoblocking.E)
Thedoctorshouldchoosethebesttreatmentforeachpatient,insteadofallowingvolunteers
tobeassignedatrandomtoatreatment.
62)
63)
Aresearcherwouldliketoinvestigatewhetherpeoplesufferingfrominsomniacanbehelpedbytakingyogaclasses.Shedesignsanexperimentasfollows.Shewillobtainagroupofvolunteerswhoaresufferingfrominsomniaandwhodonotcurrentlypracticeyoga.Eachpersonsdegreeofinsomniaatthestartoftheexperimentwillbeevaluated.Shewillinvestigatewhetheryogaclasseseverydayorthreetimesperweekaremoreeffective.Sothefactoryogawillhave3levels(noyoga,yogathreetimesaweek,yogaeveryday).Eachvolunteerwillchoosewhichgrouptheywouldliketobepartof.Attheendofasuitabletimeperiod,forexampletwomonths,eachpersonsdegreeofinsomniawillagainbeevaluated.Theimprovementforthethreegroupswillthenbecompared.Thepersonevaluatingtheinsomnialevelswillbeblindedtowhichgroupthepatientswerein.Identifythemostseriousflawinthisexperiment.
A) Thevolunteerswerenotselectedrandomly.B)
Thepersonevaluatingtheinsomnialevelscouldhavebeenbiased.C)
Therewasnoplacebogroup.D) Therewasnoblocking.E)
Volunteerschosetheirtreatmentinsteadofbeingrandomlyassignedtooneofthegroups.
63)
64)
Aneducationalresearcherhasdesignedtwodifferentmethodsforteachingastatisticscourseandwouldliketoinvestigatewhichismoreeffective.Hedesignsanexperimentasfollows.Hewillobtainagroupofvolunteerstatisticsstudents.Volunteerswillberandomlyassignedtooneoftwogroups.Group1willbetaughtthestatisticscoursebyAnnaClarkusingmethodAandgroup2willbetaughtbyBobBeaumanusingmethodB.Attheendofthesemester,studentswillalltakethesametest.Thenthescoresforthetwogroupswillbecompared.Thepersongradingthetestswillbeblindedtowhichgroupstudentswerein.Identifythemostseriousflawinthisexperiment.
A) Thereisnoblocking.B) Thereisaconfoundingvariable-
namelytheteacher.C)
Sincethereisnorandomassignment,therecouldbelurkingvariables.D)
Thepersongradingthetestsmayhavebeenbiased.E)
Volunteersshouldhavebeenselectedrandomly.
64)
18
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65)
Amanufactureroftennisracketshasdesignedanewracketandwouldliketoinvestigatewhetherplayerswillpreferittotheirpreviousdesign.Thecompanyobtains100volunteertennisplayers.Volunteersarerandomlyassignedtooneoftwogroups.Group1willusethecompanyspreviousracketfirstandthenewracketsecond.Group2willusethenewracketfirstandthecompanyspreviousracketsecond.Eachplayerwillserve30timeswitheachracket.Thenthepercentageofgoodserveswiththetworacketswillbecompared.Theplayersareblindedtowhichrackettheyareusing.Also,thepersonrecordingthepercentageofgoodservesisblindedtowhichrackettheplayersuse.Ifthegroupofvolunteersconsistsof50professionaltennisplayersand50beginners,howcouldtheexperimentbeimproved?
A)
Usematching-matcheachprofessionalplayerwithabeginningplayerbeforeassigningplayerstooneofthetwogroups.
B)
Addanotherfactor-levelofplayer,sothattherewillbefourtreatments:newraketandbeginner,newracketandprofessional,previousracketandbeginner,previousracketandprofessional.
C)
Haveplayerschoosetheirgroupinsteadofassigningthemrandomlytoagroup.D)
Useblocking-firstdividethevolunteersintoprofessionaltennisplayersandbeginners.
Withineachblockrandomlyassignvolunteerstooneofthetwogroups.E)
Includeaplacebo.
65)
Provideanappropriateresponse.66)
Moredogsarebeingdiagnosedwiththyroidproblemsthanhavebeendiagnosedinthepast.A
researcheridentified50puppieswithoutthyroidproblemsandkeptrecordsoftheirdietsforseveralyearstoseeifanydevelopedthyroidproblems.Thisisa(n)...
A) blockedexperimentB) retrospectivestudyC) surveyD)
prospectivestudyE) randomizedexperiment
66)
67) Placebosareatoolfor...A) controlB) samplingC) blindingD)
blockingE) randomization
67)
68) Double-blindinginexperimentsisimportantsothatI.
Theevaluatorsdonotknowwhichtreatmentgrouptheparticipantsarein.II.
Theparticipantsdonotknowwhichtreatmentgrouptheyarein.III.
Nooneknowswhichtreatmentanyoftheparticipantsisgetting.
A) IonlyB) IIIonlyC) IandIID) I,II,andIIIE) IIonly
68)
19
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69) Whichofthefollowingisnotrequiredinanexperimentaldesign?A)
controlB) replicationC) blockingD) randomizationE)
Allarerequiredinanexperimentaldesign.
69)
70)
Aresearcherwantstocomparetheeffectofanewtypeofshampooonhaircondition.Theresearcherbelievesthatmenandwomenmayreacttotheshampoodifferently.Additionally,theresearcherbelievesthattheshampoowillreactdifferentlyonhairthatisdyed.Thesubjectsaresplitintofourgroups:menwhodyetheirhairmenwhodonotdyetheirhair;womenwhodyetheirhair;womenwhodonotdyetheirhair.Subjectsineachgrouparerandomlyassignedtothenewshampooandtheoldshampoo.Thisexperiment...
A)
hastwofactors(genderandwhetherhairisdyed)blockedbyshampootype.B)
iscompletelyrandomized.C)
hasthreefactors(shampootype,gender,whetherhairisdyed).D)
hastwofactors(shampootypeandwhetherhairisdyed)blockedbygender.E)
hasonefactor(shampootype),blockedbygenderandwhetherhairisdyed.
70)
20
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AnswerKeyTestname:CHAPTER13EXPERIMENTSANDOBSERVATIONALSTUDIES
1) B2) C3) B4) C5) C6) B7) B8) A9) C10) C11) D12) C13) C14) C15)
C16) C17) E18) D19) C20) C21) D22) A23) B24) B25) A26) D27) C28)
C29) D30) D31) B32) C33) D34) A35) C36) B37) B38) D39) C40) C41)
B42) C43) A44) C45) A46) A47) C48) B49) A50) B
21
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AnswerKeyTestname:CHAPTER13EXPERIMENTSANDOBSERVATIONALSTUDIES
51) A52) C53) B54) A55) D56) B57) C58) C59) A60) B61) E62) A63)
E64) B65) D66) D67) C68) C69) C70) E
22
