Evidence-based library and information practice (EBLIP) was adapted from evidence-based medicine (EBM). In doing so, problems of EBM might affect EBLIP. One issue already known in medicine which may eventually reach the field of library and information sciences (LIS) is the phenomenon of "evidence reversal". An evidence reversal (ER) occurs when original information supporting a practice is contradicted by newer information concluded from a study of higher quality, meaning the study was more rigorous and less biased. Knowledge of ER will allow librarians and information specialists to improve the guidance they provide to professionals and researchers in other fields. For example, health librarians who support clinicians and health researchers and need to understand ER. Also, librarians and information specialists should be aware of this phenomenon as they are bound to eventually encounter conflicting evidence to inform their practice.