Chapter 9

Question 1

Cluster Sampling

Answer 1

We arrive at the ultimate set of elements to be included in the sample by first sampling in terms of larger groupings – clusters. The clusters are selected by simple or stratified methods; and if not all the elements in these cluster are to be included in the sample, the ultimate selection from within the clusters is also carried out on a simple or stratified random sampling basis.

Question 2

Multistage Area Sample

Answer 2

a cluster sampling plan that uses geographic areas as the initial sampling units, ending with a sample of households and then individuals within households at the final stage.

Question 3

Multistage Sampling

Answer 3

the procedure moves through a series of stages from more inclusive to less inclusive sampling units until we finally arrive at the population elements that constitute the desired sample.

Question 4

Primary Sampling Units (PSU)

Answer 4

are selected from the population of counties and metropolitan areas in the United States.

Question 5

Random Number Generator

Answer 5

has an advantage over a list of random numbers (as it appears in many statistics textbooks) because it oculd easily be programmed to generate only numbers in the desired range versus having many numbers that are out of range and unusable.

Question 6

Sampling Error

Answer 6

Even if our sampling frame is accurate and complete and our method of random selection is without error, our sample will not exactly match the population from which it is drawn on any given characteristic. This unavoidable discrepancy is referred to as the sampling error, the difference in the distribution of characteristics between a sample and the population as a whole.

Question 7

Sampling Frame

Answer 7

the list or other specification of the population from which elements are drawn to form a sample is referred to as the sampling frame.

Question 8

Sampling Without Replacement

Answer 8

If a number corresponding to an element that is already in the sample comes up a second time, it is simply ignored and the next number drawn; this corresponds to sampling without replacement.

Question 9

Simple Random Sample

Answer 9

Drawing a simple random sample requires either a list or some other systematic enumeration of the population elements.

Question 10

Strata

Answer 10

can be based on a single criterion (ex: sex, age, gender, etc.) or a combination of 2 or more criterions (ex: age and sex, males 21 and over, etc.).

Question 11

Stratified Random Sampling

Answer 11

the population is first divided into 2 or more strata. In stratified random sampling, a simple random sample is taken from each stratum, and the subsamples are then joined to form the total sample

Question 12

Systematic Sampling

Answer 12

involves choosing elements in such a way that choices are not independent.