1.1. Types of Data Flashcards
Statistics…
The science of gathering, analysing, interpreting and presenting data.
Population…
The whole of something (i.e. the entire class).
Sample…
A subset of the population.
Census…
Data gathered from the entire population.
Descriptive statistics…
Summarises the characteristics of a dataset.
Inferential statistics…
Uses sample data to reach a conclusion about the population from which the sample was drawn.
Parameter…
A descripive measure of the population.
μ: population mean.
σ2: population variance.
σ: population standard deviation.
Statistic…
A descriptive measure of a sample.
x: sample mean (x has a horizontal line on top).
s2: sample variance.
s: sample standard deviation.
Element…
The entities on which data are collected (i.e. participants).
Observations…
The set of measurements obtained for a particular element (i.e. what the researchers want to find out).
Variable…
A characteristic of interest for the element (i.e. age or gender).
Nominal data…
Labels or names used to identify an attribute of the element (i.e. hair and eye colour).
This cannot be ordered.
Ordinal data…
Numbers or categories that are used to indicate a rank or order (i.e. exam scores).
The relative magnitudes are meaningful and can therefore be ordered.
Interval data…
Data that shows properties of ordinal data, but the intervals between the values are expressed in terms of a fixed unit of measure (i.e. temperature).
This is always numeric.
Ratio…
Data that shows properties of interval data, but the location of the origin is zero (i.e. height, time and weight).
Nothing exists for the variable at the zero point and the data cannot be negative.
