ST 715 - Sampling Theory Flashcards

1621845922	Representative Sample	characteristics of interest can be estimated from the sample with a known degree of accuracy	0
1621845923	Observation unit	An object on which a measurement is taken	1
1621845924	Target Population	Complete collection of observations we want to study	2
1621845925	Sample	Subset of a population	3
1621845926	Sampled Population	The collection of all possible observation units that might have been chosen in a sample; the population from which the sample was taken.	4
1621845927	Sampling Unit	A unit that can be selected fro a sample. [ex. We want to sample individuals but can't. We instead sample households and survey individuals. Sampling units are the households and observation units are the individuals]	5
1621845928	Sampling frame	A list, map or other specification of sampling units in the population from which a sample may be selected	6
1623187559	Selection bias	occurs when some part of the target population is not in the sampled population, or more, generally, when some population units are sampled at a different rate than intended	7
1623187560	Sample of convenience	often biased; units that are easiest to select or are most likely to respond are usually not representative of the harder-to-select or non-responding units	8
1623187561	judgement sample	investigator chooses his or her judgement to select the specific units to be included in the sample	9
1623187562	under-coverage	failing to include the target population in the sampling frame	10
1623187563	overcoverage	including population units in the sampling frame that are not in the target population	11
1623187564	nonresponse	failing to obtain responses from all of the chosen sample	12
1623187565	measurement error	when the response in a survey differs from the true value	13
1623187566	measurement bias	occurs when the response has a tendency to differ from the true value in one direction	14
1623187567	sampling error	error that results from taking one sample instead of examining the whole population	15
1623187568	non-sampling errors	any errors that cannot be attributed to the sample-to-sample variability (selection bias and measurement error)	16