研究生课程“营销管理”绝密-CH16课件

1、Exploring Marketing ResearchWilliam G. ZikmundChapter 16: Sampling Designs and Sampling ProceduresSampling TerminologySamplePopulation or universePopulation elementCensusSampleSubset of a larger populationPopulationAny complete groupPeopleSales territoriesStoresCensusInvestigation of all individual

2、elements that make up a populationDefine the target populationSelect a sampling frameConduct fieldworkDetermine if a probability or nonprobability sampling method will be chosenPlan procedure for selecting sampling unitsDetermine sample sizeSelect actual sampling unitsStages in the Selectionof a Sam

3、pleTarget PopulationRelevant populationOperationally defineComic book reader?Sampling FrameA list of elements from which the sample may be drawnWorking populationMailing lists - data base marketersSampling frame errorSampling UnitsGroup selected for the samplePrimary Sampling Units (PSU)Secondary Sa

4、mpling UnitsTertiary Sampling UnitsRandom Sampling ErrorThe difference between the sample results and the result of a census conducted using identical proceduresStatistical fluctuation due to chance variationsSystematic ErrorsNonsampling errorsUnrepresentative sample resultsNot due to chanceDue to s

5、tudy design or imperfections in executionErrors Associated with SamplingSampling frame errorRandom sampling errorNonresponse errorTwo Major Categories of SamplingProbability samplingKnown, nonzero probability for every elementNonprobability samplingProbability of selecting any particular member is u

6、nknownNonprobability SamplingConvenienceJudgmentQuotaSnowballProbability SamplingSimple random sampleSystematic sampleStratified sampleCluster sampleMultistage area sampleConvenience Sampling Also called haphazard or accidental samplingThe sampling procedure of obtaining the people or units that are

7、 most conveniently availableJudgment Sampling Also called purposive sampling An experienced individual selects the sample based on his or her judgment about some appropriate characteristics required of the sample memberQuota Sampling Ensures that the various subgroups in a population are represented

8、 on pertinent sample characteristicsTo the exact extent that the investigators desireIt should not be confused with stratified sampling.Snowball Sampling A variety of procedures Initial respondents are selected by probability methods Additional respondents are obtained from information provided by t

9、he initial respondentsSimple Random Sampling A sampling procedure that ensures that each element in the population will have an equal chance of being included in the sampleSystematic Sampling A simple processEvery nth name from the list will be drawnStratified SamplingProbability sampleSubsamples ar

10、e drawn within different strataEach stratum is more or less equal on some characteristicDo not confuse with quota sampleCluster SamplingThe purpose of cluster sampling is to sample economically while retaining the characteristics of a probability sample.The primary sampling unit is no longer the ind

11、ividual element in the population The primary sampling unit is a larger cluster of elements located in proximity to one another Population ElementPossible Clusters in the United StatesU.S. adult populationStatesCountiesMetropolitan Statistical AreaCensus tractsBlocksHouseholdsExamples of ClustersPop

12、ulation ElementPossible Clusters in the United StatesCollege seniorsCollegesManufacturing firmsCountiesMetropolitan Statistical AreasLocalitiesPlantsExamples of ClustersPopulation ElementPossible Clusters in the United StatesAirline travelersAirportsPlanesSports fansFootball stadiumsBasketball arena

13、sBaseball parksExamples of ClustersWhat is the Appropriate Sample Design?Degree of accuracyResourcesTimeAdvanced knowledge of the populationNational versus localNeed for statistical analysisInternet Sampling is UniqueInternet surveys allow researchers to rapidly reach a large sample. Speed is both a

14、n advantage and a disadvantage. Sample size requirements can be met overnight or almost instantaneously. Survey should be kept open long enough so all sample units can participate.Internet SamplingMajor disadvantage lack of computer ownership and Internet access among certain segments of the populat

15、ionYet Internet samples may be representative of a target populations. target population - visitors to a particular Web site. Hard to reach subjects may participateWeb Site VisitorsUnrestricted samples are clearly convenience samplesRandomly selecting visitorsQuestionnaire request randomly pops up Over- representing the more frequent visitors Panel SamplesTypically yield a high response rate Members may be compensated for their time with a sweepstake or a small, cash incentive. Database on membersDemographic and other information from previous questionnairesSelect quota samples ba