Student learning throughout the program should be relatively stable and not depend on who conducts the assessment. It does not have to be right, just consistent. Reliability is the extent to which a measurement tool gives consistent results.
Instead, be mindful of your assessment’s limitations, but go forward with implementing improvement plans. While you should try to take steps to improve the reliability and validity of your assessment, you should not become paralyzed in your ability to draw conclusions from your assessment results and continuously focus your efforts on redeveloping your assessment instruments rather than using the results to try and improve student learning. Reliability and validity are important concepts in assessment, however, the demands for reliability and validity in SLO assessment are not usually as rigorous as in research.
