Probability Sampling
Sampling method in which each element has an equal probability of being chosen and is the most common and user-friendly method of selecting a probability sample
Simple random sampling
A preexisting group of people who represent the pool of recruitment opportunities for the sample
Convenience sampling
A sample or method in which all people or things involved have an equal chance of being chosen
Random
A selected set of correlated questionnaire items created to assess a specific construct that been operationally defined
Scale
A method of probability sampling involving the selection of elements from an ordered sampling frame in which the first element is selected at random, and each additional element is selected using a sampling interval equal to the sampling frame size divided by the target sample size
Systematic Random Sampling
Selects participants based on characteristics of a population and study objectives
Purposive Sampling
Random error in measurement resulting from unknown or unpredictable causes
Noise
A set of questionnaire items that independently adds to the measure of something that may, in fact, be tangible
Index
A method of probability sampling that involves the division of a population into smaller groups or strata that are formed based on members' shared attributes or characteristics
Stratified simple random sample
A sampling method that requires that representative individuals are chosen from a specific subgroup
Quota Sampling
Any kind of measurement error that leads to systematic differences between an observed measurement and its true value
Systematic Error
The degree to which an instrument consistently measures a construct across items and time points
Reliability
A form of sampling that divides a targeted population into groups or clusters and then draws a random sample of clusters; all elements from each cluster are selected
Multistage Cluster Sampling
A sampling method that recruits qualifying participants through its initial participants, creating tan ever-expanding number of people who may be recruited for a given study
Snowball Sampling
A form of systematic error that occurs when a participant is asked about events, behaviors, and so on that occurred in the past
Recall bias
The degree to which an instrument measures what it is supposed to measure
Validity