Tukey honestly significant Difference testMultiple comparison testFisher least significant differenceLeast significant difference formulaLeast significant difference PDFLeast significant difference WikipediaLeast significant difference explained

Fisher's Least Significant Difference: Definition + Example

文章推薦指數： 80 %
投票人數：10人

A one-way ANOVA is used to determine whether or not there is a statistically significant difference between the means of three or more ... Skiptocontent Menu About Course BasicStats MachineLearning SoftwareTutorials Excel GoogleSheets MongoDB Python R SAS SPSS Stata TI-84 Tools Calculators CriticalValueTables Glossary PostedonApril12,2021byZach Aone-wayANOVAisusedtodeterminewhetherornotthereisastatisticallysignificantdifferencebetweenthemeansofthreeormoreindependentgroups. ThehypothesesusedinanANOVAareasfollows: H0:Themeansareequalforeachgroup. HA:Atleastoneofthemeansisdifferentfromtheothers. Ifthep-valuefromtheANOVAislessthansomesignificancelevel(likeα=.05),wecanrejectthenullhypothesisandconcludethatatleastoneofthegroupmeansisdifferentfromtheothers. Butinordertofindoutexactlywhichgroupsaredifferentfromeachother,wemustconductapost-hoctest. Onecommonlyusedpost-hoctestisFisher’sleastsignificantdifferencetest. Toperformthistest,wefirstcalculatethefollowingteststatistic: LSD=t.025,DFw*√MSW(1/n1+1/n1) where: t.025,DFw:Thet-criticalvaluefromthet-distributiontablewithα=.025andDFwisthedegreesoffreedomwithingroupsfromtheANOVAtable. MSW:ThemeansquareswithingroupsfromtheANOVAtable. n1,n2:Thesamplesizesofeachgroup Wecanthencomparethemeandifferencebetweeneachgrouptothisteststatistic.Iftheabsolutevalueofthemeandifferencebetweentwogroupsisgreaterthantheteststatistic,wecandeclarethatthereisastatisticallysignificantdifferencebetweenthegroupmeans. ThefollowingexampleshowshowtoperformFisher’sleastsignificantdifferencetestinpractice. Example:Fisher’sLeastSignificanceDifferenceTest Supposeaprofessorwantstoknowwhetherornotthreedifferentstudyingtechniquesleadtodifferentexamscoresamongstudents.Totestthis,sherandomlyassigns10studentstouseeachstudyingtechniqueandrecordstheirexamscores. Thefollowingtableshowstheexamscoresforeachstudentbasedonthestudyingtechniquetheyused: Theprofessorperformsaone-wayANOVAandgetthefollowingresults: Sincethep-valueintheANOVAtable(.018771)islessthan.05,wecanconcludethatnotallofthemeanexamscoresbetweenthethreegroupsareequal. Thus,wecanproceedtoperformFisher’sleastsignificantdifferencetesttodeterminewhichgroupmeansaredifferent. UsingvaluesfromtheoutputoftheANOVA,wecancalculateFisher’steststatisticas: LSD=t.025,DFw*√MSW(1/n1+1/n1) LSD=t.025,27*√36.948*(1/10+1/10) LSD=2.052*√7.3896 LSD=5.578 Wecanthencalculatetheabsolutemeandifferencebetweeneachgroup: Technique1vs.Technique2:|80–85.8|=5.8 Technique1vs.Technique3:|80–88|=8 Technique2vs.Technique3:|85.8–88|=2.2 Theabsolutemeandifferencesbetweentechnique1vs.technique2andtechnique1vs.technique3aregreaterthanFisher’steststatistic,thuswecanconcludethatthesetechniquesleadtostatisticallysignificantlydifferentmeanexamscores. Wecanalsoconcludethatthereisnosignificantdifferenceinmeanexamscoresbetweentechnique2andtechnique3. PublishedbyZach ViewallpostsbyZach Postnavigation Prev5Real-LifeExamplesoftheGeometricDistributionNextHowtoPerformWelch’sANOVAinR(Step-by-Step) LeaveaReplyCancelreplyYouremailaddresswillnotbepublished.Requiredfieldsaremarked*Comment*Name* Email* Website Δ Search Searchfor: Search ABOUT Statologyisasitethatmakeslearningstatisticseasybyexplainingtopicsinsimpleandstraightforwardways.Learnmoreaboutus. StatologyStudyStatologyStudyistheultimateonlinestatisticsstudyguidethathelpsyoustudyandpracticeallofthecoreconceptstaughtinanyelementarystatisticscourseandmakesyourlifesomucheasierasastudent. IntroductiontoStatisticsCourseIntroductiontoStatisticsisourpremieronlinevideocoursethatteachesyouallofthetopicscoveredinintroductorystatistics.Getstartedwithourcoursetoday. RecentPosts GoogleSheets:Formulafor“IfTimeisGreaterThan” GoogleSheets:CreatePivotTablewithUniqueCounts GoogleSheets:CreatePivotTablewithCountofOccurrences

請為這篇文章評分？

延伸文章資訊