Chapter 3

Research Methods in Clinical Psychology

Set E

Line of Best


A straight line used as a best approximation of a summary of all the points in a scattergram.


Statistically accepted ways of assessing the strength of a particular finding across a number of different studies.

Longitudinal Studies

Research which takes measures from the same participants at two or more different times in order to specify the time relationships between variables. This may extend over many years or over a participant’s whole lifetime.

Multiple-Baseline Design

An experimental design in which the researcher studies several behaviours at a time.

Natural Experiments

Research which allows researchers to observe the effects on behaviour of a naturally occurring ‘manipulation’ (such as an earthquake).

Lifetime Prevalence

The frequency of a disorder within a lifetime.

Mixed Designs

Research which uses the non-random assignment of participants to groups in an experiment.


A hypothetical description of a process or mechanism (such as a process or psychological mechanism involved in psychopathology).