Year 1 Chapter 1: Data Collection Flashcards
Define population.
The whole set of items that are of interest.
What is a census?
An observation of every member of a population.
What is a sample?
A selection of observations taken from a subset of the population which is used to find out information about the population as a whole.
What is a sampling unit?
Individual units of population.
What is a sampling frame?
A lists of individually named or numbered sampling units.
What is a simple random sample?
A sample where every sample has an equal chance of being selected.
What is systematic sampling?
Where the required elements are chosen at regular intervals from an ordered list.
What is stratified sampling?
Where the population is divided into mutually exclusive strata (e.g. males and females) and a random sample is taken from each.
What is quota sampling?
Where an interviewer selects a sample that reflects the characteristics of the whole population.
What is opportunity sampling?
Where the sample is taken from people who are available at the time the study is carried out and who fit the criteria you are looking for.
What are quantitative variables/data?
Variables associated with numerical observations.
What are qualitative variables/data?
Variables associated with non-numerical observations.
What are continuous variables/data?
Variables that can take any value in a given range. (Decimals e.g. height)
What are discrete variables/data?
Variables that can take only specific values in a given range. (Only integers e.g. quantity of an object).
What is a class boundary in a grouped frequency table?
The maximum and minimum values that belong in each class.
