Chapter 5 Flashcards
What is a population?
The set of individuals of interest to a researcher. A set of entities concerning which statistical inferences are to be drawn
what is a sample?
A subset of a population
What is the target population?
It’s THE POPULATION, the set of individuals who have the characteristics required by the researcher.
what is the accessible population?
A portion of the target population (population) consisting of individuals who are accessible to be recruited as participants in the study.
what is sampling?
The variety of ways of selecting individuals to participate in a research study.
what is sample representativeness?
The extent to which the CHARACTERISTICS of a sample reflect those of the population.
what is a representative sample?
A sample with the same characteristics as the population
What is a biased sample?
a sample with different characteristics from those of the population
what is selection bias or sampling bias?
when participants or subjects are selected in a manner that increases the probability of obtaining a biased sample.
What is probability sampling?
what is a random process?
The population is known and each individual has a specifiable probability of being selected.
A sampling process that ensures that each individual in the population has an equal chance of being selected.
What is non-probability sampling?
the population is NOT completely known, individual probabilities cannot be known, and the sampling method is based on factors based on common sense or ease.
What sampling technique usually has a biased sample?
Non-probability sampling
what is simple random sampling (under probability sampling)?
a sample is obtained using a random process to select participants from a list containing the total population
what is systematic sampling?
A sample is obtained by selecting every nth participant from a list containing the total population after a random start
what is systematic sampling (under probability sampling)?
A sample is obtained by selecting every nth participant from a list containing the total population after a random start
What is stratified random (under probability sampling)?
What is proportionate stratified (under probability sampling)?
A sample is obtained by dividing the population into subgroups (strata) and then randomly selecting equal numbers from each of the subgroups
A sample is obtained by dividing the population into subgroups (strata) and then randomly selecting from each startup a number of participants so that the proportions in the sample correspond to the proportions in the population (***sample will be perfectly representative of the population)
What is cluster sampling (under probability sampling)?
Instead of selecting individuals, a sample is obtained by randomly sleeting clusters (preexisting groups) from a list of all the clusters that exist within the population
what is convenience sampling (under NON probability sampling)?
A sample is obtained by selecting individual participants who are easy to get (sample is probably biased)
what is quota sampling (under NON probability sampling)?
A same is obtained by identifying subgroups to be included, then establishing quotas for individuals to be selected through convenience from each subgroup (sample is probably biased)
Which type of sampling do experimental psychologists usually use?
Non-random sampling (non-probability)
