Date of Award

Fall 2011

Access Type

Thesis - Open Access

Degree Name

Master of Science in Human Factors & Systems


Human Factors and Systems

Committee Chair

Shawn Doherty, Ph.D.

First Committee Member

Jason Kring, Ph.D.

Second Committee Member

Lynn Koller, Ph.D.


The change probability effect is a term coined by Beck et al. (2004) and it suggests that changes that are expected or "probable" are detected more easily than changes that are unexpected or "improbable". This research study investigates the change probability effect and the differences between observers who are looking for changes and those who are unaware that changes may exist. The results suggest that observers who are not expecting a change to occur are more likely to detect an improbable change than a probable change. The findings from this study have real world applications and also have implications for change blindness research studies.