Descriptive statistics are summary statistics that quantitatively describe or summarize features of a collection of information.
Statistical inference is the process of using data analysis to deduce properties of an underlying probability distribution.
Psychologist Stanley Smith Stevens defined nominal, ordinal, interval, and ratio scales. Nominal measurements have no meaningful rank order among values.
When full census data cannot be collected, statisticians collect sample data by developing specific experiment designs and survey samples.
In order to use a sample as a guide to an entire population, it is important that it truly represents the overall population.
Interpretation of statistical information can often involve the development of a null hypothesis, which is usually (but not necessarily) that no relationship exists among variables.
Most studies only sample part of a population. Confidence intervals allow statisticians to express how closely the sample estimate matches the true value in the whole population.