Definitions Flashcards
What is a population?
A population is the whole set of items that are of interest.
What is a census?
A census observes or measures every member of a population.
What is a sample?
A sample is 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 are individual units of a population known as?
Sampling units
What are sampling units of a population?
Are individually named or numbered to form a list called a sampling frame.
What is a simple random sample?
when the size is ānā, every sample has an equal chance of being selected.
What is systematic sampling?
The required elements are chosen at regular intervals from an ordered list.
What is stratified sampling?
The population is divided into mutually exclusive strata and a random sample is taken from each. i.e. males and female
What are the methods of non-random sampling?
Quota sampling
Opportunity sampling
What are the methods of sampling?
Simple random
systematic
stratified
What is quota sampling?
When an interviewer selects a sample that reflects characteristics of the whole population.
What is opportunity sampling?
This consists of taking the sample from people who are closely available and who fit the criteria set out.
What are the types of data?
quantitative
qualitative
- continuous
- discrete
What is continuous data?
Variable that can take any value in a given range i.e. 2.1 2.23543
What is discrete data?
Variable that can take only specific values e.g. 1,2,3,4,
What are class boundaries?
Tells you the maximum and minimum values that belong in each class
What is the midpoint?
the average of the class boundaries
What is the class width?
The difference between the upper and lower class boundaries.
What is special about class boundaries with continuous data?
The data values have been rounded to the nearest value so you need to use the upper and lower bounds.
What variables are on the LDS?
Daily mean temperature (C)
Daily total rainfall (less than 0.05mm are tr or trace)
Daily total sunshine (nearest 1/10th of an hour)
Daily mean wind direction and windspeed. (Beaufort scale)
Daily maximum gusts
Daily maximum relative humidity (above 95% is foggy and misty)
Daily mean cloud cover (oktas) (1/8ths of the sky covered)
Daily mean visibility (Dm)
Daily mean pressure (hPa)
When was the LDS constructed between?
1987 - 2015
May to October
