1-3 Data Collection and Sampling Techniques

Question 1

How can data be collected?

Answer 1

• telephone survey
• mailed questionnaire
• personal interview
• survey records
• direct observation

Question 2

Random sampling

Answer 2

a sample obtained by using random or chance methods; a sample for which every member of the population has an equal chance of being selected

Question 3

Systematic sampling

Answer 3

a sample obtained by numbering each element in the population and then selecting every kth number from the population to be included in the sample

Question 4

Stratified sampling

Answer 4

a sample obtained by dividing the population into subgroups, called strata, according to various homogeneous characteristics and then selecting members from each stratum

Question 5

Cluster sampling

Answer 5

a sample obtained by selecting a preexisting or natural group, called a cluster, and using the members in the cluster for the sample

Question 6

Convince sampling

Answer 6

sample of subjects used because they are convenient and available

Question 7

volunteer/ self selected sampling

Answer 7

subjects who decide for themselves to participate in a statistical study

Question 8

sampling error

Answer 8

the difference between the sample measure and the corresponding population measure due to the fact that the sample is not a perfect representation of the population

Question 9

no sampling error

Answer 9

an error that occurs erroneously or from a biased sample