《英语测试》作业参考答案学习资料

第1页共1页以上仅为参考答案，简答、论述题均只列及主要的解题知识点，请您结合自我理解和课本内容进行知识掌握和巩固。如对答案等有疑义，请及时登录学院网站“辅导论坛”栏目，与老师交流探讨！《英语测试》作业参考答案1．Identifythescalesrepresentedbythefollowingkindsofdata:Solution:RawscoresfromalisteningcomprehensiontestOrdinalscaleAdjectivesonaword-associationtestNominalscalePercentilescoresfromaspellingtestOrdinalscaleSpeedofnote-takinginwordsperminuteRatioscaleI.Q.-equivalentscoresonavocabularytestIntervalscalez-scoresontheTOEFLIntervalscaleThenumberofinstrumentallymotivatedstudentsinclassNominalscale2．Giventhefollowingrawscoredistributiononaspellingtestof25items,calculate(a)ordinalratings,(b)percentagescores,(c)percentileranks:6,8,9,11,12,12,14,15,19,19,21,25.Solution:Rawscores Ordinalratings PercentageScores PercentileRanks25 1st 100 95.821 2nd 84 87.519 3rd 76 75.019 4th 76 75.015 5th 60 62.514 6th 56 54.212 7th 48 41.712 8th 48 41.711 9th 44 29.29 10th 36 20.88 11th 32 12.56 12th 24 4.23．Ifyouadministeredamultiple-choicetestofphrasalverbusagetoaclassoftenstudentsandgotthefollowingdistributionofscores:11,13,16,16,18,20,20,25,27,29,whatwouldbethecorrespondingz-scores,T-scores,andnormaldistributionareaproportionsifthestandarddeviationis5.95?Solution:Rawscoresz-scoresT-scoresNormaldistributionareaproportions291.59765.9794.49271.26162.6189.63250.92559.2582.24200.08450.8453.35200.08450.8453.3518-0.25247.4840.0516-0.58844.1227.8116-0.58844.1227.8113-1.09339.0713.7311-1.42935.717.654Inanormaldistribution,whatproportionofthescoresliebetweenplusandminusonestandarddeviation?Betweenplusandminustwostandarddeviations?Solution:Inanormaldistribution,68.3%ofscoresliebetweenplusandminusonestandarddeviation;95.5%ofscoresliebetweenplusandminustwostandarddeviation.5．Computeitemdifficultyandtheproportionincorrectforeachoftheitemsinthefollowingscoringmatrix.Identifyitemsforrejection. Items 1 2 3 4 5 1 1 0 1 1 1 2 1 1 0 0 0 3 1 1 0 0 1 Examinees 4 1 0 1 0 1 5 0 1 0 0 0 6 1 1 1 1 0 7 1 1 0 0 1 8 0 1 0 1 0 9 1 1 0 0 1 10 0 1 1 0 1Solution:Item 1 2 3 4 5Difficulty 0.7 0.8 0.4 0.3 0.6Proportionincorrect 0.3 0.2 0.6 0.7 0.4Items2and4canberejected,becauseitseemsthatitem2istooeasyanditem4istoodifficult.6．Lookatthefollowingpairedscoresonlisteningcomprehension(X)andgeneralproficiency(Y)fortenstudents: X Y 25 18 13 21 15 22 19 27 17 31 16 22 21 29 24 33 22 26 21 29Computethecorrelationcoefficientforthesescores.Pleasedoaone-tailedPearsontesttodeterminewhetheritissignificantonthelevelofsignificanceof<.05?Solution:r=0.273.ThecriticalvalueforPearson’rofthesignificanceof<.05,onetailedtestwhenthedegreeoffreedomequalsto8is0.5494.Sincer=0.273<0.5494,itisnotsignificant.7．Ninestudentshavetakentwodifferentaptitudetestsandgotthefollowingtestresult.ComputethePearsonproductmomentcorrelationcoefficient.Anddeterminewhetheritissignificantonthelevelofsignificanceof<.05?StudentNo. 01 02 03 04 05 06 07 08 09TestA 56 60 61 62 65 67 71 71 74TestB 34 26 62 30 30 28 34 36 40Solution:r=-0.0176.Criticalvalueis0.6664.Andr=-0.0176<0.6664,soitisnotstatisticallysignificant.

8．Lookatthefollowingscoringmatrixfortwentystudents:ItemStudent12345Score110111=SUM(LEFT)4211001=SUM(LEFT)3301010=SUM(LEFT)2401001=SUM(LEFT)2511110=SUM(LEFT)4611011=SUM(LEFT)4710101=SUM(LEFT)3801011=SUM(LEFT)3911011=SUM(LEFT)41011010=SUM(LEFT)31100101=SUM(LEFT)21201011=SUM(LEFT)31311010=SUM(LEFT)31411001=SUM(LEFT)31511111=SUM(LEFT)51601001=SUM(LEFT)21701110=SUM(LEFT)31810011=SUM(LEFT)31901011=SUM(LEFT)32011111=SUM(LEFT)5Computethepointbiserialcorrelationcoefficientforeachofthefiveitemswithtotalscore.Solution:ItemOne:0.639ItemTwo:0.112ItemThree:0.422ItemFour:0.512ItemFive:0.1299．Whatdowemeanbycorrelationinstatistics?Solution:Correlationisastatisticalrelationbetweentwoormorevariablessuchthatsystematicchangesinthevalueofonevariableareaccompaniedbysystematicchangesintheother.Generally,correlationdoesnotsuggestcause-effectrelationship.10．Pleasestatethedifferencebetweentheclassroomtestsandexternaltests.Solution:Theaimoftheclassroomtestisdifferentfromthatoftheexternalexamination.Externalexaminationsaregenerallyconcernedwithevaluationforthepurposeofselection,theclassroomtestisconcernedwithevaluationforthepurposeofenablingteacherstoincreasetheirowneffectivenessbymakingadjustmentsintheirteachingtoenablecertaingroupsofstudentsorindividualsintheclasstobenefitmore.11．MakeasimpleclarificationontheClassicalTrueScoreModelandenumerateitsdemerits.Solution:Theclassicaltheoryistheearliesttheoryofmeasurement.Theclassicaltheoryisalsoreferredtoastheclassicalreliabilitytheorybecauseitsmajortaskistoestimatethereliabilityoftheobservedscoresofatest.Thatis,itattemptstoestimatethestrengthoftherelationshipbetweentheobservedscoreandthetruescore.Itisalsosometimesreferredtoasthetruescoretheorybecauseitstheoreticalderivationsarebasedonamathematicalmodelknownasthetruescoremodel.Inatestingsituation,wefirstdeviseascalingruletochangeasetofresponsesintoanumericalobservedscore.Nextweinferthattheobservedscorefaithfullyreflectsatruescore.Finally,weinferthatthetruescoretruthfullyreflectsthequantityofaconstruct,whichmayormaynotexit.ClassicalTrueScoreModelhasthefollowingdemerits:1)thevaluesofcommonlyuseditemstatisticsintestdevelopmentsuchasitemdifficultyanditemdiscriminationdependontheparticularexamineesamplesinwhichtheyareobtained;2)comparisonsofexamineesonanabilitymeasuredbyasetoftestitemscomprisingatestarelimitedtosituationsinwhichexamineesareadministeredthesame(orparallel)testitems;3)oneofthefundamentalconcepts,testreliability,isdefinedintermsofparallelforms;4)itprovidesnobasisfordetermininghowanexamineemightperformwhenconfrontedwithatestitem;5)itpresumesthatthevarianceoferrorsofmeasurementisthesameforallexaminees.12．Pleasewritefivemultiple-choiceitemsonsomegrammaticalelements(tense,agreement,etc.).Omitted.13．Whatisthedifferencebetweencriterionreferencedtestandnormreferencedtest?Solution:Characteristicallycriterion-referencedtestsaredevisedbeforetheinstructionitselfisdesigned.Thetestmustmatchteachingobjectivesperfectly,sothatanytendencyoftheteacherto“teachtothetest”wouldbepermissibleinthatattainingobjectiveswouldtherebybeassured.Acriterionorcut-offscoreissetinadvance(usually80to90percentofthetotalpossiblescore),andthosewhodonotmeetthecriterionarerequiredtorepeatthecourse.Studentsarenotevaluatedbycomparisonwiththeachievementofotherstudents,butinsteadtheirachievementismeasuredwithrespecttothedegreeoftheirlearningormasteryoftheprespecifiedcontentdomain.Norm-referencedorstandardizedtestsarequitedifferentfromcriterion-referencedtestsinanumberofrespects;although,onceagain,someoftheidenticalitemsmaybeusedundercertainconditions.Bydefinition,anorm-referencedtestmusthavebeenpreviouslyadministeredtoalargesampleofpeoplefromthetargetpopulation(e.g.,1,000ormore).Acceptablestandardsofachievementcanonlybedeterminedafterthetesthasbeendevelopedandadministered.Suchstandardsarefoundbyreferencetothemeanoraveragescoreofotherstudentsfromthesamepopulation.14．Whatiscomputerizedadaptivetesting?Solution:Adaptivetesting,orcomputeradaptivetesting,isaprocessoftestadministrationinwhichtestitemsareselectedonthebasisoftheexaminee’sresponsetopreviouslyadministereditems.Mostcommonly,suchanapproachwould,foranexamineewhoexperiencessuccesswithagivenitem,resultinthepurposefulpresentationofanitemofgreaterdifficulty.Theexamineewhoexperiencedfailurewithagivenitemwouldnextencounteranitemoflowerdifficulty.Witheachresponse,thecomputermakesarevisedestimateoftheexaminee'sability;eachrevivedestimatebecomesmorereliable.Thetestisterminatedwhentheestimatereachesaspecifiedlevelofreliability.WecansaythatcomputerizedadaptivetestingtakesasitstheoreticalbasistheItemResponseTheory(IRT)orthelatenttraittheory,whichmakesthegeneralassumptionthatexamineeperformanceonapooloftestitemsisassumedtodependonalimitednumberofpsychologicaltraitscalledabilities.15．Whatisitemdifficulty?Howtocomputeitemdifficulty?Solution:Itemdifficultyisdeterminedastheproportionofcorrectresponses,signifiedbytheletter“p”.Theformulaforitemdifficultythenis

where,p=difficulty,proportioncorrect,∑Cr=thesumofcorrectresponses,N=thenumberofexaminees.16．Howareitemdifficulty,itemdiscriminabilityrepresentedinitemresponsetheory?Solution:Theideaofitemdifficultyasalocationindexwillbeexaminedfirst.InFigure1,threeitemcharacteristiccurvesarepresentedonthesamegraph.Allhavethesamelevelofdiscriminationbutdifferwithrespecttodifficulty.Thelefthandcurverepresentsaneasyitembecausetheprobabilityofcorrectresponseishighforlow-abilityexamineesandapproaches1forhigh-abilityexaminees.Thecentercurverepresentsanitemofmediumdifficultybecausetheprobabilityofcorrectresponseislowatthelowestabilitylevels,around.5inthemiddleoftheabilityscaleandnear1atthehighestabilitylevels.Therighthandcurverepresentsaharditem.Theprobabilityofcorrectresponseislowformostoftheabilityscaleandincreasesonlywhenthehigherabilitylevelsarereached.Evenatthehighestabilitylevelshown(+3),theprobabilityofcorrectresponseisonly.8forthemostdifficultitem.TheconceptofdiscriminationisillustratedinFigure2.Thisfigurecontainsthreeitemcharacteristiccurveshavingthesamedifficultylevelbutdifferingwithrespecttodiscrimination.Theuppercurvehasahighlevelofdiscriminationsincethecurveisquitesteepinthemiddlewheretheprobabilityofcorrectresponsechangesveryrapidlyasabilityincreases.Justashortdistancetotheleftofthemiddleofthecurve,theprobabilityofcorrectresponseismuchlessthan.5,andashortdistancetotherighttheprobabilityismuchgreaterthan.5.Themiddlecurverepresentsanitemwithamoderatelevelofdiscrimination.Theslopeofthiscurveismuchlessthanthepreviouscurveandtheprobabilityofcorrectresponsechangeslessdramaticallythanthepreviouscurveastheabilitylevelincreases.However,theprobabilityofcorrectresponseisnearzeroforthelowest-abilityexamineesandnear1forthehighest-abilityexaminees.Thethirdcurverepresentsanitemwithlowdiscrimination.Thecurvehasaverysmallslopeandtheprobabilityofcorrectresponsechangesslowlyoverthefullrangeofabilitiesshown.Evenatlowabilitylevels,theprobabilityofcorrectresponseisreasonablylarge,anditincreasesonlyslightlywhenhighabilitylevelsarereached.17．Whatgeneralrelationshipexistsbetweentestreliabilityandthenumberofitemsonthetest?Solution:Reliabilityisaffectedbythenumberofitemsinthetest.Wecanreadilyunderstandhowithappensthatwithmoreitemsinthetestagreaterrangeofscoresispossible,andthusexamineesaremorewidelydispersedalongthescoringcontinuum.Inthiswayitcanbesaidthatwehavegreaterpersonseparabilityandlesslikelihoodthatexamineeswouldchangerankorderonrepeatedadministrationsofthetest.18．Whatdoesitmeanifwesayacorrelationcoefficientissignificantatthep<.05level?Solution:“P<0.05”meansthatbasedonthetest,thereislessthana5%chancethatwearewronginrejectingthenullhypothesis.Andwearegenerallysafetosaythatthetwovariablesundertestarecorrelated.19．Whatarethesourcesofmeasurementerrorsinlanguagetest?Solution:Usuallywhenweadministerandscoreatest,someerrorofmeasurementispresent.Avarietyofkindsofmeasurementerrorcanintroducefluctuationsinobservedscoresandthusreducereliability.Thesedifferentkindsofmeasurementerrorcanbecausedfromthetest-takers’side,thescorers’sideandtheadministrationofthetest.Avarietyofchangesmaytakeplacewithinthetest-takerthateitherwillintroduceerroronrepeatedadministrationsorwillchangethetest-taker’struescorefromtimeonetotimetwo.Iftruescoreschange,correlationsbetweenrepeatedsetsofobservedscoreswillgodown,causingustounderestimatethereliabilityofthetest.Temporarychangesintheexamineemayintroducemeasurementerror.Influencessuchasfatigue,sickness,emotionaldisturbance,andpracticeeffectmaycausetheexaminee'sobservedscoretotemporarilydeviatefromhisorhertruescore,orthatscorewhichreflectshisorheractualability.Subjectivityinscoringormechanicalerrorsinthescoringprocessmayintroduceinconsistenciesinscoresandproduceunreliablemeasurement.Thesekindsofinconsistenciesusuallyoccurwithinorbetweentheratersthemselves.Inconsistenciesintheadministrativeprocessmayintroducemeasurementerrorandthusreducetestreliability.Thisismostobservableinsituationswherethetestisadministeredtodifferentgroupsindifferentlocationsorondifferentdays,butmayalsoappearwithinoneadministrationinonelocation.20．Whatisthemeaningofmeasuresofdispersion?Solution:Measuresofdispersiondescribehowthedatavariesorisdispersed(spreadout).Thetwomostcommonlyusedmeasuresofdispersionaretherangeandthestandarddeviation.Ratherthanshowinghowdataaresimilar,theyshowhowdatadiffers(itsvariation,spread,ordispersion).21．Listfivecommonproblemsattheitemwritingstage.Provideoneexampleofeachproblemtypeandcorrecttheitemifnecessary.Solution:1.MixedResponseItemsaresometimespreparedtotestaspecificskillorcompetence,butcloseexaminationoftheresponseoptionsrevealsthattheoptionsactuallymeasureabilityinskillareasotherthanthoseintended.Forexample: John flowerstothepartylastnight. a)carries C)lifts b)carried d)liftedItshouldbebetterifwehave, a)carries C)iscarrying b)carried d)hascarried2.LengthCuesFrequentlythelongestandmostexplicitoptionavailableistheobviousanswer.Considerthefollowingexample:Inthestory,themerchantwasunhappybecauseita)rained. c)waswindy.b)wasdark. d)waswindyandrainyandhehadforgottenhisraincoat.3.NonsenseDistractorsFormostpurposes,nonsensedistractorsaretobeavoided.Nonsenseoptionshavetwobasicproblems.First,theytendtobeweakdistractors.Second,theyfrequentlyhavenegative“wash-back”oninstruction;i.e.,thestudentsmaylearnerrorsfromtheexaminationitself.Considerthefollowingexample:Theysaidtheya.hadgone.c.havewent.b.hadgo.d.hadwent.Obviouslydistractors(b),(c),and(d)containstructuresthatdonotoccuringrammaticallyacceptableEnglishforclassroomuse.4.TrickQuestionsForsometeachersitisalwaysatemptationtoincludetrickquesionsonanexamination.Itisdifficulttosaywhethertheteacher'smotiveistodisplaycleverness,toembarrassthestudentsforrevenge,ormerelytoensuretestdifficulty.Thepointisthatsuchquestionsmakeforbothinaccuratemeasurementandpoorpedagogy.Considerthefollowingexample:Whenisitnotappropriatenottobeabsentfromclass?