When we conduct research we usually collect a large amount of information from our subjects. Statistics provide us with a way of describing large amounts of data with a much smaller number of summary figures (descriptive statistics). In this way, we can see if there are obvious differences or similarities between groups within our data.

In psychology we often want to know if there is a 'real' difference between two or more groups of subjects or a difference in individual subjects' scores across time or under different conditions. Statistics can provide us with estimates of the likelihood of groups within our data having different characteristics, which we can then use to make statements about the population we are interested in (inferential statistics).

But before you are ready to tackle the statistical tests, there are a few basic concepts that you need to understand...

Topics covered in this section include:
Statistical Notation
Data & Variables
Sampling & Inference