Elementary-statistics-Introduction-to-Statistics

1.1-1Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.LectureSlidesElementaryStatisticsEleventhEditionandtheTriolaStatisticsSeriesbyMarioF.Triola1.1-2Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.Chapter1IntroductiontoStatistics1-1ReviewandPreview1-2StatisticalThinking1-3TypesofData1-4CriticalThinking1-5CollectingSampleData1.1-3Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.Section1-1ReviewandPreview1.1-4Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.PreviewPolls,studies,surveysandotherdatacollectingtoolscollectdatafromasmallpartofalargergroupsothatwecanlearnsomethingaboutthelargergroup.Thisisacommonandimportantgoalofstatistics:Learnaboutalargegroupbyexaminingdatafromsomeofitsmembers.1.1-5Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.PreviewInthiscontext,thetermssampleandpopulationhavespecialmeaning.Formaldefinitionsfortheseandotherbasictermswillbegivenhere.Inthissectionwewilllookatsomeofthewaystodescribedata.1.1-6Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.Datacollectionsofobservations(suchasmeasurements,genders,surveyresponses)Data1.1-7Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.Statisticsisthescienceofplanningstudiesandexperiments,obtainingdata,andthenorganizing,summarizing,presenting,analyzing,interpreting,anddrawingconclusionsbasedonthedataStatistics1.1-8Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.PopulationPopulationthecompletecollectionofallindividuals(scores,people,measurements,andsoon)tobestudied;thecollectioniscompleteinthesensethatitincludesalloftheindividualstobestudied1.1-9Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.CensusversusSampleCensusCollectionofdatafromeverymemberofapopulationSampleSubcollectionofmembersselectedfromapopulation1.1-10Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.ChapterKeyConceptsSampledatamustbecollectedinanappropriateway,suchasthroughaprocessofrandomselection.Ifsampledataarenotcollectedinanappropriateway,thedatamaybesocompletelyuselessthatnoamountofstatisticaltorturingcansalvagethem.1.1-11Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.Section1-2StatisticalThinking1.1-12Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.KeyConceptThissectionintroducesbasicprinciplesofstatisticalthinkingusedthroughoutthisbook.Whetherconductingstatisticalanalysisofdatathatwehavecollected,oranalyzingastatisticalanalysisdonebysomeoneelse,weshouldnotrelyonblindacceptanceofmathematicalcalculation.Weshouldconsiderthesefactors:1.1-13Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.ContextofthedataSourceofthedataSamplingmethodConclusionsPracticalimplicationsKeyConcept(continued)1.1-14Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.ContextWhatdothevaluesrepresent?Wheredidthedatacomefrom?Whyweretheycollected?Anunderstandingofthecontextwilldirectlyaffectthestatisticalprocedureused.1.1-15Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.SourceofdataIsthesourceobjective?Isthesourcebiased?Istheresomeincentivetodistortorspinresultstosupportsomeself-servingposition?Istheresomethingtogainorlosebydistortingresults?Bevigilantandskepticalofstudiesfromsourcesthatmaybebiased.1.1-16Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.SamplingMethodDoesthemethodchosengreatlyinfluencethevalidityoftheconclusion?Voluntaryresponse(orself-selected)samplesoftenhavebias(thosewithspecialinterestaremorelikelytoparticipate).Thesesamples’resultsarenotnecessarilyvalid.Othermethodsaremorelikelytoproducegoodresults.1.1-17Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.ConclusionsMakestatementsthatarecleartothosewithoutanunderstandingofstatisticsanditsterminology.Avoidmakingstatementsnotjustifiedbythestatisticalanalysis.1.1-18Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.PracticalImplicationsStatepracticalimplicationsoftheresults.TheremayexistsomestatisticalsignificanceyettheremaybeNOpracticalsignificance.Commonsensemightsuggestthatthefindingdoesnotmakeenoughofadifferencetojustifyitsuseortobepractical.1.1-19Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.StatisticalSignificanceConsiderthelikelihoodofgettingtheresultsbychance.Ifresultscouldeasilyoccurbychance,thentheyarenotstatisticallysignificant.Ifthelikelihoodofgettingtheresultsissosmall,thentheresultsarestatisticallysignificant.1.1-20Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.Section1-3TypesofData1.1-21Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.KeyConceptThesubjectofstatisticsislargelyaboutusingsampledatatomakeinferences(orgeneralizations)aboutanentirepopulation.Itisessentialtoknowandunderstandthedefinitionsthatfollow.1.1-22Copyright©2010,2007,2004PearsonEducation,Inc.AllRightsReserved.Parameteranumericalmeasurementdescribingsomecharacteristicofapopulation.populationparameterParameter1.1-23Copyright©2010,2007