National Institute of Justice National Institute of Justice. Research. Development. Evaluation. Office of Justice Programs
Crime Solutions.gov
skip navigationHome  |  Help  |  Contact Us  |  Site Map   |  Glossary
Reliable Research. Real Results. skip navigation
skip navigation Additional Resources:

skip navigation

Glossary

History (Evidence Rating Element)

An event that takes place between the pretest (data collected prior to the treatment beginning) and the posttest (data collected after the treatment ends) that has nothing to do with the treatment but may impact observed outcomes.  History is a potential threat to Internal Validity. See Program Review and Rating from Start to Finish for more information.