r statistical application development data characteristics

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1、1DataCharacteristicsDataconsistsofobservationsacrossdifferenttypesofvariables,anditisvitalthatanyDataAnalystunderstandstheseintricaciesattheearlieststageofexposuretostatisticalanalysis.Thischapterrecognizestheimportanceofdataandbeginswithatemplateofadummyquestionnaireandthen

2、proceedswiththenitty-grittiesofthesubject.Wethenexplainhowuncertaintycreepsintothedomainofcomputerscience.Thechaptercloseswithcoverageofimportantfamiliesofdiscreteandcontinuousrandomvariables.Wewillcoverthefollowingtopics:Identificationofthemainvariabletypesasnominal,categor

3、ical,andcontinuousvariablesTheuncertaintyarisinginmanyrealexperimentsRinstallationandpackagesThemathematicalformofdiscreteandcontinuousrandomvariablesandtheirapplicationsDataCharacteristicsQuestionnaireanditscomponentsThegoalofthissectionisintroductionofnumerousvariabletypes

4、atthefirstpossibleoccasion.Traditionally,anintroductorycoursebeginswiththeelementsofprobabilitytheoryandthenbuildsuptherequisitesleadingtorandomvariables.Thisconventionisdroppedinthisbookandwebeginstraightawaywithdata.Thereisaprimaryreasonforchoosingthispath.Theapproachbuild

5、sonwhatthereaderisalreadyfamiliarwithandthenconnectsitwiththeessentialframeworkofthesubject.Itisverylikelythattheuserisfamiliarwithquestionnaires.Aquestionnairemaybeaskedafterthebirthofababywithaviewtoaidthehospitalinthestudyabouttheexperienceofthemother,thehealthstatusofthe

6、baby,andtheconcernsofimmediateguardiansofthenewborn.Amulti-storedepartmentmayinstantlyrequestthecustomertofillinashortquestionnaireforcapturingthecustomer'ssatisfactionafterthesaleofaproduct.Acustomer'ssatisfactionfollowingtheserviceoftheirvehicle(seethedetailedexamplediscus

7、sedlater)canbecapturedthroughafewqueries.Thequestionnairesmayariseindifferentformsthanjustmerelyonpaper.Theymaybesentviae-mail,telephone,shortmessageservice(SMS),andsoon.Asanexample,onemayreceiveanSMSthatseeksamandatoryresponseinaYes/Noform.Ane-mailmayarriveintheOutlookinbox

8、,whichrequirestherecipienttorespondthroughavoteforanyofthesethreeoptions,"W