How we change what others think, feel, believe and do
Proxy Pre-test design
In this design, the 'pre-test' is not actually done, but some form of proxy is or alternative method is used to represent the first test.
In the Recollection Proxy Pretest design, the subject is asked to recall or imagine the previous value of the variable being assessed, such as how they felt about an issue beforehand.
In the Archived Proxy Pretest design, existing records are examined, such as previous ability test results or qualifications.
In design notation, this might be written as (with the proxy pre-test parenthesized):
An experiment in new teaching methods uses existing SAT scores as a pre-test evaluation.
A new motivation system is brought into use in a company. The standard employee satisfaction survey is used as both a pre- and post-test.
The Proxy Pre-test can be very useful when it would be difficult or impossible to do a pre-test. It can also save time and money -- things which researchers often have in short supply.
The Recollection Proxy Pretest is very common, but can suffer from the effects of bias, and a whole range of memory effects.
Where standard tests or measures already exist, such as in schools, then the Archived Proxy is very useful as the standard tests may provide a reliable and valid method of measurement.