Understanding the NVR scores - GL Education

Understanding the NVR scores. Articles in this section: Raw score; Standard age Score (SAS); Stanines ... Contact [email protected] for support ... Home KnowledgeBase Assessments NVRTSupport Administration UnderstandingtheNVRscores BacktoAdministration NVRTSupportHome Importantinformation Administration DigitaltestsfromGLAssessment IntroductiontoNon-VerbalReasoningDigital UseofNVRDigital Timing Administration Pupilswithspecialassessmentneeds Thetestenvironment Unexpectedincidentsduringatestsession NVRDigitalTestwisereports WhatdotheNVRDigitaltestscomprise NVR8&9 NVR10&11 NVR12-14 UsingNVRscoresinschools UnderstandingtheNVRscores Checklistforteachers TestwiseTechnicalSupportTeam ScoringandReportingService Non-verbalReasoning Findoutmore UnderstandingtheNVRscores Articlesinthissection: Rawscore StandardageScore(SAS) Stanines Nationalpercentilerank(NPR) Confidencebands Non-VerbalReasoning(digitalonly)willnotbeavailableafter3December.Contact[email protected]forsupport Rawscore Therawscoreissimplythetotalnumberofcorrectanswersobtainedbythepupil.Thesescorescanbeconvertedtothreetypesofnormativescorescalledstandardagescores(SAS),staninesandpercentiles.Thesearedescribedbelow. StandardageScore(SAS) Onewaytomakearawscoremorereadilyunderstandablewouldbetoconvertittoapercentage:forexample,‘33outof50’becomes66%.However,thepercentageonitsowndoesnottellustheaveragescoreofallthepupilsorhowspreadoutthescoresare,whereasstandardagescoresdorelatetothesestatistics. Inordertoprovideastandardage(orstandardscore)scale,sometestsarestandardisedsothattheaveragestandardagescoreforanyagegroupisalways100.Thismakesiteasytotellwhetherapupilisaboveorbelowthenationalaverage.Thespreadofscores(the‘standarddeviation’)isalsosettoplusorminus15points,sothatforanyagegroupabouttwo-thirdsofthepupilsinthenationalsamplewillhaveastandardisedscoreofbetween85and115.NVRandVRwerestandardisedin1992usinganationalsampleofmaintainedandindependentschoolsinEnglandandWales. Rawscoresareconvertedtostandardagescoresthatallowyoutocomparethelevelofcognitivedevelopmentofanindividualwiththelevelsofotherpupilsinthesameagegroup.Thepropertiesofstandardagescoresmeanthatapproximatelytwo-thirdsofpupilsintheagegroupscorebetween85and115,approximately95percentscorebetween70and130,andover99percentscorebetween60and140.Figure1.1showsthefrequencydistribution,knownasthenormaldistribution,forstandardagescores,staninesandpercentiles. Standardagescoreshavethreeparticularbenefits,asdescribedbelow. •Theyplaceapupil’sperformanceonareadilyunderstandablescale.Aswehaveseenabove,standardagescoresallowapupil’sperformancetobereadilyinterpreted.Itisimmediatelydeduciblefromthescoreitselfthatanon-verbalreasoningscoreof95indicatesalevelofperformancejustbelowthenationalaverage,butwellwithintheaveragerange. •Anallowancecanbemadeforthedifferentagesofthepupils.Inatypicalclasstheoldestpupilsareverynearly12monthsolderthantheyoungest.Almostinvariably,olderpupilsachieveslightlyhigherrawscoresintestsandexaminationsthanyoungerpupils.However,standardagescoresarederivedinsuchawaythattheagesofthepupilsaretakenintoaccountbycomparingapupilonlywithothersofthesameage.Anolderpupilmayinfactgainahigherrawscorethanayoungerpupil,buthavealowerstandardisedscore.Thisisbecausetheolderpupilisbeingcomparedwithotherolderpupilsinthenormgroup.Pupilsofdifferentageswhogainthesamestandardagescorehavedoneequallywell,witheachbeingjudgedinrelationtotheirstandingamongpupilsoftheirownage. •Scoresfromdifferenttestscanbemeaningfullyaddedorcompared.Standardisedscoresformosttestscoverthesamerange,from60-to140+.Henceapupil’sstanding,insaymathematicsandEnglish,canbecompareddirectlyusingstandardisedscores.Itisnotmeaningfultoaddtogetherrawscoresfromtestsofdifferentlengthordifficulty.However,shouldyouwishtoaddstandardisedscoresfrommorethanonetest–forexample,inordertoobtainasingleoverallmeasureofattainment–theycanbemeaningfullycombined. Stanines Standardscoresrunfrom60-to140+andgivedifferentiated,finelygradedinformationontheperformanceofeachpupil.However,sometimesashorthandsummaryismoreuseful.Stanines,shortfor‘standardnines’,arejustninesummaryscorebandscalculateddirectlyfromthestandardscores,asshowninTable1.3.Basedonthenationalstandardisation,wecansaywhatproportionofpupilsareexpectedwithineachstanine,andthesearealsogiveninthetable.Thebroadnatureofstaninesminimisesover-interpretationofsmall,insignificantdifferencesamongtestscores.Staninesarethereforeparticularlyusefulinreportingtestinformationtopupilsandtoparents,astheyarerelativelyeasytounderstandandinterpret. Table1.3:StaninesscorebandsforNVR Nationalpercentilerank(NPR) Thisindicatesthepercentageofpupilsinthenationalsamplewhoobtainastandardagescoreatorbelowaparticularscore.Forexample,apupilwithastandardagescoreof108hasanationalpercentilerank(NPR)of70.Heorshehasperformedaswellas,orbetterthan,70percentofpupilsofhisorheragegroup.AnNPRof50isaverageforanagegroup. Confidencebands Pupils’standardscoresarealsoshownasaverticallinewithahorizontallineshowingthe90percentconfidenceband.Itisrecognisedthatanytestscorerepresentsaperformanceonaparticularday,andthescoreshouldthereforebeplacedwithinsuchaconfidenceband.Ifthetestweretakenagain,ninetimesoutoftenonewouldexpectthescoretofallwithinthisrange. Previous:DigitaltestsfromGLAssessment Next:Checklistforteachers Non-verbalReasoning Findoutmore Searchforanotherknowledgetopic