Chapter 9 Selecting the Sample Flashcards
A _______ is defined as the entire group under study,
population
A ______ is defined as an accounting of the complete population.
census
A _______ is a subset of the population that suitably represents that entire group.
sample
A ________ is the basic level of investigation.
sample unit
A ________ is a master source of sample units in the population.
sample frame
_______, which is the degree to which the sample frame fails to account for all of the population.
sample frame error
_______ is any error in a survey that occurs because a sample is used.
Sampling error
Whenever a sample is taken, the survey will reflect _____.
sampling error
Taking a ______ is less expensive than taking a census.
sample
All sample designs fall into one of two categories:
probability or nonprobability
________ are samples where members of the population have a known chance (probability) of being selected into the sample.
Probability samples
_______, on the other hand, are samples where the chances (probability) of selecting members from the population into the sample are unknown.
Nonprobability samples
With ______, the method determines the chances, or probability, of a sample unit being selected into the sample.
probability sampling
With __________, the probability of being selected into the sample is equal for all members of the population.
simple random sampling
Formula for simple random sample probability
Probability of selection = sample size/ population size
With _________, the probability of selection into the sample is known for all members of the population.
simple random sampling
Examples of simple random sampling include the ______ and ______
random device method and the random numbers method.
The _________, sometimes referred to as “probability device method,” involves using an apparatus or procedure to ensure that every member of the population has the same chance of being selected into the sample.
random device method
The “_____” is a form of simple random sampling.
random device
A random number embodies simple _________
random sampling assumptions.
_________, which are numbers whose chance nature is assured.
random numbers
Using _______ to draw a simple random sample requires a complete accounting of the population.
random numbers
________ (RDD) is used in telephone surveys to overcome the problems of unlisted and new telephone numbers.
Random digit dialing
________ overcomes problems of unlisted and new telephone numbers.
Random digit dialing
______ is a way to select a random sample from a directory or list, and it is much more efficient than simple random sampling.
Systematic sampling
Formula for skip interval
Skip interval=population list size/sample size
_________ is more efficient than simple random sampling because only one or a very few random numbers need to be drawn at the beginning.
Systematic sampling
With _________, the small loss in sampling precision is counterbalanced by its economic savings.
systematic sampling
_______, the population is divided into subgroups or “clusters,” each of which could represent the entire population.
cluster sampling
_______ , the researcher subdivides the population to be surveyed into geographic areas, such as census tracts, cities, neighborhoods, or any other convenient and identifiable geographic designation
area sampling
_________, the researcher may believe that the various geographic areas (clusters) are sufficiently identical for results in just one area to be generalized to the full population.
one-step area sample approach
_________ approach to the sampling process. That is, for the first step, the researcher could select a random sample of areas, then for the second step, he or she could decide on a probability method to sample individuals within the chosen areas.
two-step area sample
________ employs either a one-step or two-step approach.
Area sampling
________, which separates the population into different subgroups and then samples all of the subgroups.
stratified sampling
_________ distribution has a long tail on one end and a short tail on the other.
skewed population
__________ is used when the researcher is working with a “skewed” population and wishes to achieve high statistical efficiency.
Stratified sampling
With stratified random sampling, one takes a skewed population and identifies the subgroups or _______ contained within it.
strata
________, whose formula takes into consideration the sizes of the strata relative to the total population size, and applies those proportions to the strata’s means.
weighted mean
A stratified sample may require the calculation of a ________ to achieve accuracy.
weighted mean
Formula for weighted mean
Meanpopulation=(meanA)(proportionA)+(meanB)(proportionB)
Researchers should select a basis for stratification that reveals ______ across the strata.
different responses
________ which is some easily determined characteristic of each population member,
surrogate measure,
If the strata sample sizes are scaled to their relative sizes in the population, the research design reflects a ________
proportionate stratified sample
________, meaning that for the same sample size, researchers may obtain equivalent precision among the strata
statistical efficiency
__________, and a weighted formula needs to be used because the strata sizes do not reflect their relative proportions in the population
disproportionate stratified sampling
Samples drawn from groups to which the researcher has easy access are called _________
convenience samples
With __________ methods, some members of the population do not have any chance of being included in the sample.
nonprobability sampling
_________ are convenience samples.
Mall intercepts
Convenience samples may ________ the population.
misrepresent
Sometimes called “snowball samples,” ________ require respondents to provide the names of more prospective respondents
chain referral samples
One source19 identifies four advantages of chain referral sampling:
(1) find samples quickly, (2) low cost, (3) works for hesitant respondents, and (4) able to access special populations, such as drug users
_______ require that a judgment or “educated guess” be made as to who should represent the population.
purposive samples
When a researcher specifies percentages of the total sample for various types of individuals to be interviewed and selects them via nonprobability sampling, this is called a _______
quota sample
______ rely on key characteristics to define the composition of the sample.
Quota samples
_______ are appropriate when researchers have a detailed demographic profile of the population on which to base the sample.
Quota samples
______ are comprised of individuals who have consented to participate in online surveys
Online panel samples
Types of online samples include
online panel samples, river samples, and email list samples.
A ________ is created via the use of banners, pop-ups, or other online devices that invite website visitors to take part in a survey.
river sample
________ are those purchased or otherwise procured from a person or company that has compiled email addresses of members of the population of interest.
Email list samples
A ________ lists all the steps necessary to draw a sample.
sample plan
