A type of nonrandom sample in which the researcher first identifies general categories into which cases or people will be selected then selects a predetermined number of cases in each category
A type of nonrandom sample in which the researcher uses a wide range of methods to locate all possible cases of a highly specific and difficult to reach population
A type of nonrandom sample in which a researcher selects unusual or nonconforming cases purposely as a way to provide greater insight into social processes or a setting; especially used by qualitative researchers
A type of nonrandom sample in which the researcher begins with one case then, based on information about interrelationships from that case, identifies other cases, and then repeats the process again and again
A type of nonrandom sample in which a researcher tries to find as many relevant cases as possible until there is no new information or diversity from the cases
An iterative sampling technique associated with the grounded theory approach in which the sample size is determined when the data reach theoretical saturation
The number of cases in the sample divided by the number of cases in the population or the sampling frame, or the proportion of the population in the sample
A type of sample in which the researcher uses a random-number table or similar mathematical random process so that each sampling element in the population will have an equal probability of being selected
A law-like mathematical relationship stating that whenever many random samples are drawn from a population and plotted, a normal distribution is formed, and the centre of such a distribution for a variable is equal to its population parameter
A range of values, usually a little higher and lower than a specific value found in a sample, within which a researcher has a specified and high degree of confidence that the population parameter lies
The inverse of the sampling ratio, which is used in systematic sampling to select cases. The sampling interval (i.e., 1 in k, where k is some number) tells the researcher how to select elements from a sampling frame by skipping elements in the frame before selecting one for the sample
A type of random sample that uses multiple stages and is often used to cover wide geographic areas in which aggregated units are randomly selected; samples are then drawn from the sampled aggregated units, or clusters
A branch of applied mathematics or statistics based on a random sample. It lets a researcher make precise statements about the level of confidence they have in the results of a sample being equal to the population parameter
A problem in survey research question wording that occurs when two ideas are combined into one question and it is unclear whether the answer is for the combination of both or one or the other question
A type of survey research question in which respondents are likely to cover up or lie about their true behaviour or beliefs because they fear a loss of self-image or may appear to be engaging in undesirable or deviant behaviour
A question with two or more parts in survey research. The answer to the first part of the question determines which of two different questions a respondent receives next