Most studies collect more data than is possible to interpret just by
looking at the raw data.
Usually, the data are summarised and
presented in a way which helps to reveal the true patterns in the
2.1 Types of variables
is a characteristic or measurement that varies from one subject to another.
It is useful to distinguish between four types of variables.
The variable has categories or levels with no natural order;
e.g. sex, country of birth.
The variable has categories or levels with a natural order;
e.g. pain (none, mild, moderate, severe).
The values are numerical but only certain values are
possible; e.g. household size, number of children.
The values are numerical and all values in some
continuous range are possible; e.g. blood pressure, weight.
variables are called
variables in SPSS Statistics.
variable is also called a
variable with only
possible values is also called a
variable; e.g. male/female, dead/alive, yes/no.