- Environment (or situation); manipulate (or control); variables (or factors).
- Both are designed to uncover cause- and-effect relationships; the comparative method is only a ‘thought experiment’ by the researcher, whereas the laboratory experiment is a practical experiment on real people.
- (a) Society is so complex it is impossible to identify and control all possible variables; experiments cannot be used to study the past. (b) Difficulty obtaining informed consent from groups e.g. children who are unable to understand what is being proposed; the experiment may harm the subjects.
- The problem of subjects behaving differently because they are being observed.
- (a) An independent variable is a factor that is altered by the researcher, in order to discover its effects; (b) experimenter bias refers to the ways in which the researcher’s own views or behaviour may influence the result of an experiment.
- It avoids artificiality; can be used to study past events; poses no ethical problems such as harming or deceiving the subjects.
