Chapter 5- Selecting Research Participants Flashcards
Population
the entire set of individuals of interest to a researcher. Although the entire population usually does not participate in a research study, the results from the study are generalized to the entire population.
sample
a set of individuals selected from a population and usually is intended to represent the population in a research study.
target population
A group defined by a researcher’s specific interests
accessible population
the easily available segment of a target population. Researchers typically select their samples from this type of population
the representativeness of a sample
refers to the extent to which the characteristics of the sample accurately reflect the characteristics of the population.
a representative sample
is a sample with the same characteristics as the population.
biased sample
a sample with different characteristics from those of the population.
selection/sampling bias
occurs when participants or subjects are selected in a manner that increases the probability of obtaining a biased sample.
law of large numbers
In the field of statistics, the principle that states that the larger the sample size, the more likely it is that values obtained from the sample are similar to the actual values for the population.
sampling
the process of selecting individuals to participate in a research study.
probability sampling
the entire population is known, each individual in the population has a specifiable probability of selection, and sampling occurs by a random process based on the probabilities.
random process
procedure that produces one outcome from a set of possible outcomes. The outcome must be unpredictable each time, and the process must guarantee that each of the possible outcomes is equally likely to occur.
nonprobability sampling
the population is not completely known, individual probabilities cannot be known, and the sampling method is based on factors such as commonsense or ease, with an effort to maintain representativeness and avoid bias.
simple random sampling
A probability sampling technique in which each individual in the population has an equal and independent chance of selection.
systematic sampling
A probability sampling technique in which a sample is obtained by selecting every nth participant from a list containing the total population after a random starting point.
