Using an animal model, a researcher was testing the capacity of a drug to block the brain damage that normally follows a stroke. The drug (Baclofen, a GABA
B
agonist) was administered to 2 of the 4 groups as follows:
Group 1 - No stroke, no drug Group 2 - Stroke, no drug Group 3 - No stroke, drug Group 4 - Stroke, drug
After treatment, all four groups were given a test of spatial learning each day for 4 days as a test of functional outcome. With lower scores indicating better learning, the results were as follows:
Psychology355StatsAssignment 1 Psychology355–StatisticalPrintoutInterpretationExercises 1.Menandwomenwerebothgiventheopportunitytonavigateavirtualmaze.Participantsweregiven6 chancestonavigatethemaze,andtheaveragetimetocompletewascomputed(avtime).Theresultswere asfollows: Average of the 6 trials Sex Mean N SD SEM Male 38.6558750 18 27.2249520 4.30464288 Female 55.8041667 18 40.1285131 6.34487502 Total 47.2300208 36 35.1469979 3.92955383 Questions(8marks:1markperquestion,2marksforthegraph) (1)Howmanypeopleparticipatedinthestudy? (2)WhataretheIV(s)andDV(s)?HowmanylevelsarethereforeachIVandwhatarethoselevels? (3)Whichgrouphadbetterperformance?Howdidyoudeterminethis? (4)Wasthedifferencesignificant? (5)ReportthestatisticinAPAformat. (6)Whywasan“independentsamples”t-testusedinsteadofa“pairedsamples”test? (7)GraphtheresultsinAPAformat(handdrawngraphsarefine). Independent Samples Test Levene’s Testfor Equalityof Variances t-testfor Equalityof Means F Sig. t df Sig.(2-tailed) avtime Equalvariances assumed 0.069 0.794 -3.034 34 0.003 Equalvariances notassumed -3.034 34.879 0.003 Psychology355StatsAssignment 2 2.Thesamestudydescribedabovewasconductedagain,butnowthelocationoftheendpoint (directions)wasdescribedusingeitherEuclideanfeatures(goNorth10steps)orLandmarkfeatures (turnrightatthepyramid).Theresultswere: Report avtime Sex Directions Mean N SD SEM Male Euclidean 38.08325 20 26.7007 5.9705 Landmark 39.2285 20 28.4217 6.3553 Total 38.655875 40 27.225 4.3046 Female Euclidean 58.6583333 20 33.5101 7.4931 Landmark 52.95 20 46.5325 10.405 Total 55.8041667 40 40.1285 6.3449 Tot Euclidean 48.3707917 40 31.6692 5.0073 Landmark 46.08925 40 38.6871 6.117 Total 47.2300208 80 35.147 3.9296 Analysis: Between-Subjects Factors Value Label N Sex 1 Male 40 2 Female 40 Direction 1 Euclidean 40 2 Landmark 40 Tests of Between-Subjects Effects Dependent Variable: avtime Source Type III Sum of Squares df Mean Square F Sig. Model 5927.028(a) 3 1975.676 3.994 0.011 Intercept 96098.547 1 96098.547 194.272 0.000 Sex 4594.946 1 4594.946 9.289 0.003 Direction 72.93 1 72.93 0.147 0.702 Sex*Direction 1259.152 1 1259.152 2.545 0.115 Error 37594.152 76 494.66 Total 139619.727 80 Corrected Total 43521.18 79 Questions(5marks:1markperquestion,2marksforthegraph) (1)Whattypeofanalysisisthis? (2)Reporttheindependentvariablesandtheirlevels. (3)Whatweretheresults(reportthemanddiscusswhattheymeanintermsoftheresearchquestion)? (4)GraphtheinteractioninAPAformat. Psychology355StatsAssignment 3 3.Aresearcherwasinterestedintherelationbetweenperformanceonthegreyscalestask(grey; negativescoresindicateastrongerleftwardspatialbias)andnumberofcollisionswiththerightwallina virtualmaze(alsoindicatingofastrongerleftwardspatialbias).Theresearcherhadalargegroupof randomlyselectedstudentscompletethegreyscalestaskandvirtualmaze.Theresultswere: grey collisions grey Pearson Correlation 1 -.265(*) Sig. (2-tailed) . 0.017 N 80 80 collisions Pearson Correlation -.265(*) 1 Sig. (2-tailed) 0.017 . N 80 80 *Correlation is significant at the 0.05 level (2-tailed) Questions:(6marks:1markperquestion) (1)Howmanypeopleparticipatedinthestudy? (2)WhataretheIV(s)andDV(s)? (3)Whatweretheresults(reportthemanddiscusswhattheymeanintermsoftheresearchquestion)? Convincedthattherewasmoretotherelationbetweenperceptualasymmetriesonthegreyscalestask andvirtualmazeperformance,theresearcherexaminedmalesandfemalesseparately: Correlational Data for Males grey collisions grey Pearson Correlation 1 -0.169 Sig. (2-tailed) . 0.298 N 40 40 collisions Pearson Correlation -0.169 1 Sig. (2-tailed) 0.298 . N 40 40 Correlational Data for Females grey collisions grey Pearson Correlation 1 -0.32 Sig. (2-tailed) . 0.0172 N 40 40 collisions Pearson Correlation -0.32 1 Sig. (2-tailed) 0.0172 . N 40 40 (5)Howmanypeoplewereineachgroup? (6)Whataretherelevantresultsafterthenewanalysis?ReporttheminAPAformatanddiscusswhat theymeanintermsoftheresearchquestion. (7)Whatdoesthissubsequentanalysistellusaboutthefirstcorrelation? Psychology355StatsAssignment 4 4.Aresearcherwasinterestedintherelationbetweendepressionandhandedness.Alargegroupof students(malesandfemales)completedthe“BeckDepressionInventory”(BDI;higherscoresindicate higherlevelsofdepression),aswellasahandednessquestionnaire.Theresultswereasfollows: Tests of Between-Subjects Effects Dependent Variable: BDI Source Type III SS df Mean Square F Sig. Hand 5.514 1 5.514 .115 .734 Sex 8.408 1 8.408 .176 .675 Hand*Sex 42.174 1 42.174 11.547 .002 Error 25548.857 534 47.844 Total 63746.000 538 Corrected Total 25603.063 537 Questions(7marks:1markperquestion) (1)Whatsortofanalysisisthis? (2)WhataretheIV(s)andDV(s)?Reportthelevelsforeachindependentvariable. (3)Werethereanysignificantmaineffects?Ifso,reportthem. (4)Werethereanysignificantinteractions?Ifso,reportthem. (5)Giventheinformationabove,canyoutellwhichgroupshavehigherlevelsofdepressionthanothers? Ifso,reportthisinformation. (6)Areadditionalstatisticaltestsarenecessary?Ifso,whichone(s)? (7)Wasthisstudyanexperiment,aquasi-experiment,oracorrelationalstudy?Why? Psychology355StatsAssignment 5 5.Aresearcherwasinterestedintherelationbetweenlateralizedbraindamageandthecomprehension ofhumour.Toinvestigatethis,theresearchergaveatestofhumourcomprehension(higherscores indicategreatercomprehension)to40adults:10maleswithRHdamage,10femaleswithRHdamage,10 maleswithLHdamage,and10femaleswithRHdamage.Theresultswereasfollows: Descriptive Statistics Dependent Variable: Humour Lesion Sex Mean Std. Deviation N Left lesion Male 70.00 3.9441 10 Female 85.00 3.5277 10 Total 77.50 8.5131 20 Right lesion Male 55.00 7.5130 10 Female 65.00 3.6209 10 Total 60.00 7.6983 20 Total Male 62.50 9.6600 20 Female 75.00 10.8337 20 Total 68.75 11.9459 40 Tests of Between-Subjects Effects Dependent Variable: Humour Source Type III SS df Mean Square F Sig. Corrected Model 4687.50 3 1562.500 64.066 .000 Intercept 189062.50 1 189062.500 7751.993 .000 Lesion 3062.50 1 3062.500 125.569 .000 Sex 1562.50 1 1562.500 64.066 .000 Lesion*Sex 62.50 1 62.500 2.563 .118 Error 878.00 36 24.389 Total 194628.00 40 Corrected Total 5565.50 39 a) R Squared = .842 (Adjusted R Squared = .829) Questions(8marks:1markperquestion,2marksforthegraph) (1)Whatsortofanalysisisthis? (2)WhataretheIV(s)andDV(s)?ReportthelevelsforeachIV. (3)Werethereanysignificantmaineffects?Ifso,reportthem. (4)Werethereanysignificantinteractions?Ifso,reportthem. (5)Giventheinformationabove,canyoutellwhichgroupswerebetteratcomprehendinghumour?Ifso, reportthisinformation. (6)Whatdotheresultsmean?Graphtheinteractiontosupportyourinterpretation. Psychology355StatsAssignment 6 6.Aresearcherwasinterestedinrecoveryafterstroke.Shetestedsomestrokepatients’abilityto perceiveprosodyinlanguage30daysaftertheirstrokeandthentestedthesameindividuals90days aftertheirstroke.Higherscoresindicatebettercomprehension.Theresultswereasfollows: Paired-Samples Statistics Mean N Std. Deviation Std. Error Mean Pair 1 TIME1 49.15 20 20.6787 4.6239 TIME2 49.60 20 19.6050 4.3838 Paired-Samples Test Paired Differences Mean Std. Deviation SEM 95% CI Difference t df Sig. (2-tailed) Lower Upper -.4500 3.9666 .8870 -2.3064 1.4064 -.507 19 .618 Questions(8marks:1markperquestion) (1)Whatsortofanalysisisthis? (2)Howmanypeopleparticipatedinthestudy? (3)WhataretheIV(s)andDV(s)?ReportthelevelsforeachIV. (4)Whichgroupwasbetteratperceivingprosody?Howdoyouknowthis? (5)Wasthedifferencesignificant?Reportthestatisticyouinterpretedtodeterminethis. Usingthesamedataset,theresearcherthencompletedthefollowinganalysis: Tests of Within-Subjects Effects Source Type III SS df Mean Square F Sig. TIME Sphericity Assumed 2.025 1 2.025 .257 .618 Greenhouse-Geisser 2.025 1.000 2.025 .257 .618 Huynh-Feldt 2.025 1.000 2.025 .257 .618 Lower-bound 2.025 1.000 2.025 .257 .618 Error (TIME) Sphericity Assumed 149.475 19 7.867 Greenhouse-Geisser 149.475 19.000 7.867 Huynh-Feldt 149.475 19.000 7.867 Lower-bound 149.475 19.000 7.867 Tests of Between-Subjects Effects Source Type III SS df Mean Square F Sig. Intercept 97515.625 1 97515.625 121.273 .000 Error 15277.875 19 804.099 (6)Whatsortofanalysisisthis? (7)Whatisthedifferencebetweenthisanalysisandthepreviousanalysis? (8)Whichanalysisismoreappropriate? Psychology355StatsAssignment 7 7.Aresearcherwasinterestedinstudyingpersonalitychangefollowingsubarachnoidhemorrhage(SAH). AgroupofSAHpatientsweregivenapersonalitytesttwice.Forthefirstadministrationtheywereasked todescribetheirpersonalitybeforetheSAH.Thesecondtimethetestwasadministered,thepatients wereaskedtodescribetheirpersonalitynow.Ageneraldifferencescorewascalculatedbysubtracting theirscoreattime1(beforetheSAH)fromtheirscoreattime2(aftertheSAH).Todeterminewhether thepersonalitychangewassignificant,theresearchperformedthefollowingtest: One-Sample Statistics N Mean Std. Deviation Std. Error Mean Personality Change 20 5.45 5.0936 1.1390 One-Sample Test Test Value = 0 t df Sig. (2-tailed) Mean Difference Personality Change 4.785 19 .000 5.4500 Questions(5marks:1markperquestion) (1)Whatsortofanalysisisthis? (2)Whatisthecomparisonvaluebeingusedintheanalysis? (3)Howmanypeopleparticipatedinthestudy? (4)WhataretheIV(s)andDV(s)?ReportthelevelsofeachIV.ExplainhowtheDVwasdetermined. (5)ReporttheresultsoftheanalysisinAPAformat.Discusswhattheresultsmeanintermsofthe researchquestion. Psychology355StatsAssignment 8 8.Usingananimalmodel,aresearcherwastestingthecapacityofadrugtoblockthebraindamagethat normallyfollowsastroke.Thedrug(Baclofen,aGABABagonist)wasadministeredto2ofthe4groupsas follows: Group1-Nostroke,nodrug Group2-Stroke,nodrug Group3-Nostroke,drug Group4-Stroke,drug Aftertreatment,allfourgroupsweregivenatestofspatiallearningeachdayfor4daysasatestof functionaloutcome.Withlowerscoresindicatingbetterlearning,theresultswereasfollows: Tests of Between-Subjects Effects Source Type III SS df Mean Square F Sig. Intercept 103632.40 1 103632.400 1485.533 .000 Stroke 6604.90 1 6604.900 94.679 .000 Drug 1768.90 1 1768.900 25.357 .000 Stroke*Drug 2016.40 1 2016.400 28.904 .000 Error 2511.40 36 69.761 Tests of Within-Subjects Effects Source Type III SS df Mean Square F Sig. DAY Sphericity Assumed 20036.650 3 6678.883 546.620 .000 Greenhouse-Geisser 20036.650 1.974 10147.773 546.620 .000 Huynh-Feldt 20036.650 2.262 8856.349 546.620 .000 Lower-bound 20036.650 1.000 20036.650 546.620 .000 DAY*STROKE Sphericity Assumed 879.150 3 293.050 23.984 .000 Greenhouse-Geisser 879.150 1.974 445.255 23.984 .000 Huynh-Feldt 879.150 2.262 388.591 23.984 .000 Lower-bound 879.150 1.000 879.150 23.984 .000 DAY*DRUG Sphericity Assumed 163.550 3 54.517 4.462 .005 Greenhouse-Geisser 163.550 1.974 82.832 4.462 .015 Huynh-Feldt 163.550 2.262 72.290 4.462 .011 Lower-bound 163.550 1.000 163.550 4.462 .042 DAY*STROKE*DRUG Sphericity Assumed 181.050 3 60.350 4.939 .003 Greenhouse-Geisser 181.050 1.974 91.695 4.939 .010 Huynh-Feldt 181.050 2.262 80.025 4.939 .007 Lower-bound 181.050 1.000 181.050 4.939 .033 Error (Day) Sphericity Assumed 1319.600 108 12.219 Greenhouse-Geisser 1319.600 71.082 18.565 Huynh-Feldt 1319.600 81.447 16.202 Lower-bound 1319.600 36.000 36.656 Questions(4marks:1markperquestion) (1)Whatsortofanalysisisthis?Whyaretheretwotables? (2)WhataretheIV(s)andDV(s)?ReportthelevelsofeachIV. (3)Whatarethesignificanteffects?ReporteachoneinAPAformat. (4)Giventheresultsabove,canyouinterpretthemeaningoftheresults?Explain.