Requested Term: Area sampling

In area 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.

Requested Term: Blind draw method

The blind draw method involves blindly choosing participants by their names or some other unique designation.

Requested Term: Census

Although a sample is a subset of a group, a census is defined as an accounting of the complete population.

Requested Term: Cluster sampling

Another form of probability sampling is known as cluster sampling, in which the population is divided into subgroups, called "clusters," each of which represents the entire population.

Requested Term: Convenience sample

Convenience samples are samples drawn at the convenience of the interviewer.

Requested Term: Disproportionate stratified sampling

But with disproportionate stratified sampling, the weighted formula needs to be used because the strata sizes do not reflect their relative proportions in the population.

Requested Term: Drop-down substitution

The drop-down substitution is often used with systematic sampling.

Requested Term: Incidence rate

As we noted in an earlier chapter, the percentage of people on a list who qualify as members of the population is referred to as the incidence rate.

Requested Term: Invitation online sampling

Invitation online sampling is when potential respondents are alerted that they may fill out a questionnaire that is hosted at a specific Web site.

Requested Term: Judgment sample

Judgment samples are somewhat different from convenience samples in concept because they require a judgment or an "educated guess" as to who should represent the population.

Requested Term: Nonprobability sample

Nonprobability samples, on the other hand, are instances in which the chances (probability) of selecting members from the population into the sample are unknown.

Requested Term: One-step area sample

In the one-step area sample approach, the researcher may believe the various geographic areas to be sufficiently identical to permit him or her to concentrate his or her attention on just one area and then generalize the results to the full population.

Requested Term: Online panel sampling

Online panel sampling refers to consumer or other respondent panels that are set up by marketing research companies for the explicit purpose of conducting online surveys with representative samples.

Requested Term: Oversampling

Oversampling is an alternative substitution method, and it takes place as a result of the researcher's knowledge of incidence rates, nonresponse rates, and unusable responses.

Requested Term: Plus-one dialing procedure

A popular variation of random digit dialing that reduces this problem is the plus-one dialing procedure in which numbers are selected from a telephone directory and a digit, such as a "1," is added to each number to determine which telephone number is then dialed.

Requested Term: Population

A population is defined as the entire group under study as specified by the objectives of the research project.

Requested Term: Probability sample

Probability samples are ones in which members of the population have a known chance (probability) of being selected into the sample.

Requested Term: Proportionate stratified sample

If the strata sample sizes are faithful to their relative sizes in the population, you have what is called a proportionate stratified sample design.

Requested Term: Quota sample

The quota sample establishes a specific quota for various types of individuals to be interviewed.

Requested Term: Random digit dialing

Random digit dialing (RDD) is used in telephone surveys to overcome the problems of unlisted and new telephone numbers.

Requested Term: Random online intercept sampling

Random online intercept sampling relies on a random selection of Web site visitors.

Requested Term: Referral sample

Referral samples, sometimes called "snowball samples," require respondents to provide the names of additional respondents.

Requested Term: Resampling

Resampling constitutes a third means of respondent substitution. Resampling is a procedure in which the sample frame is tapped for additional names after the initial sample is drawn.

Requested Term: Sample

A sample is a subset of the population that should represent that entire group.

Requested Term: Sample frame

To select a sample, you will need a sample frame, which is some master list of all the sample units in the population.

Requested Term: Sample frame error

A sample frame invariably contains sample frame error, which is the degree to which it fails to account for all of the population.

Requested Term: Sample unit

As you would expect, a sample unit is the basic level of investigation.

Requested Term: Sample validation

The essence of sample validation is to assure the client that the sample is, in fact, a representative sample of the population about which the decision maker wishes to make decisions.

Requested Term: Simple random sampling

With simple random sampling, the probability of being selected into the sample is "known" and equal for all members of the population.

Requested Term: Skewed population

A skewed population deviates quite a bit from what is assumed to be the "normal" distribution case in the use of simple random, systematic, or cluster sampling.

Requested Term: Skip interval

The researcher decides on a skip interval, which is calculated by dividing the number of names on the list by the sample size.

Requested Term: Strata

With stratified random sampling, one takes a skewed population and identifies the subgroups or strata contained within it.

Requested Term: Stratified sampling

One solution is stratified sampling, which separates the population into different subgroups and then samples all of these subgroups.

Requested Term: Surrogate measure

Usually, a surrogate measure, which is some observable or easily determined characteristic of each population member, is used to help partition or separate the population members into their various subgroupings.

Requested Term: Systematic sampling

At one time, systematic sampling, which is a way to select a random sample from a directory or list that is much more efficient (uses less effort) than with simple random sampling, was the most prevalent type of sampling technique used.

Requested Term: Table of random numbers

A more sophisticated application of simple random sampling is to use a computer-generated number based on the concept of a table of random numbers, which is a listing of numbers whose random order is assured.

Requested Term: Two-step area sample

Alternatively, he or she may employ a two-step area sample approach to the sampling process. That is, for the first step, the researcher could select a random sample of areas, and then for the second step, he or she could decide on a probability method to sample individuals within the chosen areas.

Requested Term: Weighted mean

Second, there is a procedure that allows the estimation of the overall sample mean by use of a weighted mean, 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.

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