264a Marketing Research 1

Sampling

264a Marketing Research 2

Target Population and Sampling Frame

• Specification of population of interest is the most important step.

• Sampling frame should enumerate that population– Target population

• Shoppers at Santa Monica Place

– Sampling Frame• Time? Place?

264a Marketing Research 3

Target Population and Sampling Frame

• The United States Army begins a national search for eligible recruits.

• A professional golfer begins a national campaign to sell his latest instructional video.

264a Marketing Research 4

Sample Size

• “How” you sample is much more important than “How many” you sample.

• “How”– Probability samples– Non Probability samples

• “How many”– Statistical precision– Industry standards

264a Marketing Research 5

Simple Random Sampling

• Make a list– Articulate the sampling frame

• Roll the dice– Equally likely elementary events

264a Marketing Research 6

Multistage Cluster Sampling

• Lay out primary clusters– Sample randomly

• Lay out secondary clusters– Sample randomly

• etc.

264a Marketing Research 7

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Primary

Clusters

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Secondary

Clusters Simple Random Sampling within Secondary Clusters

264a Marketing Research 8

Sample WeightingCluster 1 Sample 1 Cluster 2 Sample 2

97 54 54117 117 110 11093 10898 98 89122 122 80 8083 98 98111 10987 56 56118 73 73118 118 73 73116 53 53109 109 69 69119 78 7880 80 97 97111 9190 90 96 9683 104 104105 105 60 6097 97 101102 102101 101108 108115101 10192 92

Average 102.9 102.9 84.2 78.6

Unweighted Average 94.8 90.8Weighted Average 92.1