This handbook focuses primarily on equating test forms.
Equating is a technical procedure or process conducted to establish comparable
scores on different versions of a test, allowing them to be used interchangeably. It is
an important aspect of establishing and maintaining the technical quality of a testing
program by directly impacting the validity of assessments—the degree to which
evidence and theory support the interpretations of test scores. When two test forms
have been successfully equated, educators can validly interpret performance on one
test form as having the same substantive meaning compared to the equated score of
the other test form.
There are a number of substantive and technical issues involved in equating and
many potential pitfalls in its use. This handbook was written for decision makers to
guide them in addressing these issues and to help them avoid potential problems.
Intended as both a guide and teaching tool, it aims to provide readers with the
practical knowledge needed to make appropriate decisions, especially readers who
may have arrived at their current position from a non-technical background.
Therefore, this publication is for
- newly appointed assessment personnel coming from non-technical
disciplines who need practical guidance with regard to equating decisions
and their potential impacts
- experienced psychometric experts who may benefit by offering an equating
primer as a resource to non-psychometrician colleagues to encourage a
better understanding of the issues
- policy personnel in the position of explaining the reasoning behind prior
equating decisions or advocating the future direction of an assessment
- psychometricians who would benefit from basic models that illustrate past
decisions and how they related to policy
- anyone who might benefit from a better understanding of what equating is,
why it is done, and how common problems might be avoided.