Sampling Flashcards
What is a population or universe?
Any complete group with common characteristics
What is a population element?
Single member of a population
What is a census?
Investigation of all individual elements that make up a population
What is a sample?
- Subset of the larger population of interest
- This is the subset of group that the researcher will actually study or investigate
What is a population frame?
A list of all the elements in the population
What is a sample frame?
A list of all the elements in the population from which the sample may be drawn
What is sampling frame error?
An error which occurs when certain sample elements are not listed or are not accurately represented in a sampling frame
What is a sampling unit?
An element or group of elements subject to selection in the sample
What is inclusion/exclusion criteria?
The criteria potential participants must meet in order to be included in the study
What are the core statistical concepts?
- Descriptive statistics
- Inferential statistics
- Population parameters
- Sample statistics
What are descriptive statistics?
- Describe the data
- Measure of central tendency, frequencies, dispersion
- Trends
What are inferential statistics?
- Project characteristics of a sample to an entire population
- Make an inference about a population from a sample
- Used in hypothesis testing
What are population parameters?
- Characteristics of the population
- Variable in a population or measure characteristics of the populaiton
- Greek letters as notation
- μ = ∑X/N
What are sample statistics?
- Estimates of population parameters
- Variables in a sample or measures computed from sample data
- English letters for notation
- X̅ = ∑X/N
What is the cost associated with sampling and the solution to this?
- A loss of information
- To make up for this loss we have to ensure that the sample is representative of the population
What does representativeness determine?
The representativeness of the sample determines the extent to which generalisable inferences can be made