Chapter 6 - Sampling Flashcards
probability sampling
sampling based on a process of random selection that gives each case in the population an equal/known chance of being included in the sample
nonprobability sampling
methods of case selection other than random selection
population
the total membership of a defined class of people, objects, or events
sample
a subset of cases selected from a population
probability
the likelihood that something will occur, which may vary from 0 to 100 percent
random selection
a selection process that gives each element in a population an equal/known chance of being selected
sampling without replacement
sampling procedure where once a case is selected, it’s not returned to the sampling frame
sampling with replacement
sampling procedure where once a case is selected, it’s returned to the sampling frame
probability distribution
distribution of the probabilities for a variable, which indicates the likelihood that each category or value of the variable will occur
sampling error
the difference between an actual population value (%) and the population value estimated from a sample
sampling distribution
a rhetorical distribution of sample results for all possible samples of a given size
standard error
a statistical measure of the ‘average’ sampling error for a particular sampling distribution, which indicates how much sample results will vary from sample to sample
normal curve
a bell-shaped distribution of data that characterizes many variables and statistics, such as the sampling distribution of a proportion or mean (aka normal distribution)
confidence interval
a range (interval) within which a population value is estimated to be at a specific level of confidence
target population
the population to which researchers would like to generalize their results