Definition
Statistical inference
A statistical inference is a reasoned conclusion about a population or process drawn from data.
What it means
You use what happened in the data to say what is likely beyond the data you saw. The conclusion is not an exact fact about everyone. A well-chosen sample and consistent evidence make it stronger; a biased or tiny sample can make it weak.
Remember it
Use the part you measured to make a careful claim about the whole.
Example
A school randomly selects 60 of its 600 pupils, and 42 prefer the later lunch time. The sample suggests that a majority of pupils may prefer it, but it does not prove that exactly 420 pupils do.
Watch for
An inference reaches beyond the observed data; a summary only describes the data that was collected.
Common mix-up
A sample result does not automatically represent the population—the sampling method matters.
Exact meaning
A statistical inference is a conclusion or estimate about a wider population or process based on sample or repeated-observation data, with its strength limited by the data-collection design and variability.