Ch5 - Study Questions

population

set of individuals or other entities to which we want to be able to generalize our findings

sample

a subset of elements from the larger population

elements

the individual members of the population whose characteristics are to be measured

enumeration unti

units that contain one or more elements and that are listed in a sampling frame

sampling unit

the units actually selected in each stage of sampling

what is the difference between sampling generalizability and cross-population generalizability

sampling generalizability is the generalization from a sample of a large population to that population itself, and cross-population generalizability is when one population can be generalized to another

what is systematic bias

An overrepresentation or underrepresentation of some population characteristics in a sample resulting from the method used to select the sample

biased sample

a sample shaped by systematic sampling error

First elaboration from the statement “In general, both size of the sample and the homogeneity (sameness) of the population affect the degree of error due to chance; the proportion of the population that the sample represents does not.”

The larger the sample, the more confidence we can have in the sample’s representativeness of the population from which it was drawn.

second elaboration from the statement “In general, both size of the sample and the homogeneity (sameness) of the population affect the degree of error due to chance; the proportion of the population that the sample represents does not.”

The more homogenous the population, the more confidence we can have in the representativeness of a sample of any particular size

third elaboration from the statement “In general, both size of the sample and the homogeneity (sameness) of the population affect the degree of error due to chance; the proportion of the population that the sample represents does not.”

The fraction of the total population that a sample contains does not affect the sample’s representativeness, unless that fraction is large.

what is replacement sampling

Each element is returned to the sampling frame from which it is selected so that it may be sampled again.

what is systematic random sampling

A variant of simple random sampling, it is a little less time-consuming; method of sampling in which sample elements are selected from a list or from sequential files with every nth element being selected after the first element is selected randomly within the first interval.

what is periodicity

A sequence of elements (in a list to be sampled) that varies in some regular, periodic pattern.

how is the NCVS an example of a multistage cluster sample

it has multiple stages in which elements are selected and select participants from smaller geographic and residential stages rather than a national list.

what is quota sampling

a non-probability sampling method in which elements are selected to ensure that the sample represents certain characteristics in proportion to their prevalence in the population

What are Rubin and Rubin’s (1995) three guidelines for selecting informants and two tests for discontinuing the selection of interviewees?

Informants should be knowledgeable about the cultural arena, situation or experience being studied, willing to talk, and representative or the range of points of view

what is a sampling statistic

the value of a statistic, such as a mean, computed from sample data; an estimate of a population parameter

what is a population parameter

the value of a statistic, such as a mean, computed using the data for the entire population; a sampling statistic is an estimate of a population parameter.

what is a confidence limit

the upper and lower bounds around an estimate of a population parameter based on a sample statistic

what does a confidence level do

shows how much confidence can be placed in the estimate