data and sampling Flashcards
What is primary data?
Primary data is data that is collected directly yourself
What is secondary data?
Secondary data is data taken from an existing source such as a book or website
What must a sample of data be?
If a sample of data is collected it must represent the whole picture, called the POPULATION.
This means that it needs to be an appropriate SIZE and must avoid BIAS.
What are open questions?
Open questions are questions where any answer can be given
What are closed questions
Closed questions are questions that allows only specific answers
What is a whole population survey called?
Surveying every member of the population is called a CENSUS
What is a systematic sample?
Systematic sampling is where you sample every 5th or 10th (or similar) items
What is a stratified sample?
Taking a sample from each sub - section of the population so each group is represented in the proportion is called a STRATIFIED SAMPLE
What factors can influence the method used?
- cost
- time
What is quantitative data?
Data that is numerical
What is qualitative data?
Data that this non - numerical (words)
What is discrete data?
Discrete data is data that can only take specific values (e.g. shoe size, number of…)
What is continuous data?
Continuous data is data that can take any value in a given range (e.g. length and time)
What is grouped data?
Once data has been collected, it can be put into classes to make it easier to analyse which is called GROUPED DATA.
What is grouped data?
Once data has been collected, it can be put into classes to make it easier to analyse which is called GROUPED DATA.
