GCSE stats definitions Flashcards
Cluster Sampling - when to use
Use when data naturally splits into groups.
Cluster sampling - sampling frame
The list of clusters is the sampling frame
Cluster sampling - how to select sample
Randomly select clusters from the sampling frame to makes the sample.
Quota sampling
Group population by characteristics and interview a quota from each group
Systematic sampling
Choose a starting point in sampling frame randomly. Choose items at regular intervals
Non random sampling - comment on
Bias; is sample size sensible; how quick and easy method is;how expensive to carry out
Random Sample - definition
Every member of the population has an equal chance of being included
Random Sample - advantage
Sample is more likely to be representative of the population (provided it is large)
Choice of sample members is unbiased
Random Sample - disadvantage
Needs a full list of population
Needs a large sample size
Population - definition
Everybody/thing that could possibly be involved in an investigation
Census- definition
A survey where data is collected from every member of the population
Quantitative Data - defintion
Numerical observations or measurements
Qualitative data - definition
Non-numerical observations
Continuous Data - defintion
Data which can take any value on a continuous numerical scale
Discrete Data - definition
Data which can only take particular values on a continuous numerical scale
