Lecture Marketing research - Chapter 10: Basic sampling issues

After studying this chapter you will be able to: Understand the concept of sampling, learn the steps in developing a sampling plan, understand the concepts of sampling error and nonsampling error, understand the differences between probability samples, and nonprobability samples, understand sampling implications of surveying over the Internet.
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Lecture Marketing research - Chapter 10: Basic sampling issues Learning ObjectivesCHAPTER Ten Basic Sampling Issues Copyright © 2004 John Wiley & Sons, Inc. Learning Objectives Learning Objectives1. To understand the concept of sampling.2. To learn the steps in developing a sampling plan.3. To understand the concepts of sampling error and nonsampling error.4. To understand the differences between probability samples, and nonprobability samples.5. To understand sampling implications of surveying over the Internet. Learning ObjectivesThe Concept of Sampling To understand the concept of sampling. Sampling Defined: 1. The process of obtaining information from a subset of a larger group. 2. A market researcher takes the results from the sample to make estimates of the larger group. 3. Sampling a small percentage of a population can result in very accurate estimates. Learning ObjectivesDefinition Of Important To understand the Terms concept of sampling.Population or Universe 1. The population or population of interest is the total group of people from whom information is needed. 2. Defining the population of interest is the first step in the sampling process 3. Requires good logic and judgment 4. Based on the characteristics of current or target customerSample versus CensusCensus: Data about every member of the population.Sample: A subset of the populationFigure 10.1 Learning Steps in Developing Objectives a Sample Plan Step 7. Step 2. Choose Execute Data Collection Operational Plan Method Step1. Define the Population of Step 6. Develop Interest Step 3. Operational Plan Choose Sampling Frame Step 5. (4) Determine Select a Sample Size Sampling Method Learning ObjectivesSteps In Developing A To learn the steps in Sampling Plan developing a sample plan.Step One: Defining the Population of Interest Specifying the characteristics from whom information is needed. Define the characteristics of those that should be excluded.Step Two: Choose Data Collection Method Impacts for the sampling process.Step Three: Choosing Sampling Frame A list of elements or members from which we select units to be sampled. Learning ObjectivesSteps In Developing A To learn the steps in Sampling Plan developing a sample plan.Step Four: Select a Sampling Method The selection will depend on: • The objectives of the study • The financial resources available • Time limitations • The nature of the problem Probability Samples A known, nonzero probability of selection Learning ObjectivesSteps In Developing A To understand the steps in Sampling Plan developing a sample plan. Nonprobability Samples Elements selected in a nonrandom manner. 1. Nonrandomness—selected on the basis of convenience 2. Purposeful nonrandomness—systematically excludes or overrepresents certain subsets of the population Learning ObjectivesSteps In Developing A To understand the steps in Sampling Plan developing a sample plan. Advantages Of Probability Samples 1. Information from a representative cross-section 2. Sampling error can be computed 3. Results are projectable to the total population. Disadvantages Of Probability Samples 1. More expansive than nonprobabiity samples 2. Take more time to design and execute. Learning ObjectivesSteps In Developing A To understand the steps in Sampling Plan developing a sample plan. Disadvantages of Nonprobability Samples 1. Sampling error cannot be computed 2. Representativeness of the sample is not known 3. Result ...