BIAS SNOWBALL:
A general term that refers to the magnification of bias as it is passed through the critical appraisal process, or the magnification of bias as it is passed from group to group1,2. Such that, biased interpretations at later stages in the process are made worse because of 1) the influence of biases from early stages, and 2) the influence of new, biased information from other external sources. External information is defined as any information that is derived from outside of the critical appraisal system.
Bias Snowball is also sometimes called the Bias Snowball Effect. Bias Snowball is related to Bias Cascade, however Bias Snowball refers to when bias is magnified as it passes through the stages of the critical appraisal system. Whereas Bias Cascade, refers simply to the passing of biased information through the system without magnification. Also see: Bias Cascade, Implicit Bias, Conceptual Bias, and Bias (Definition).
References:
1. Dror IE, Morgan RM. Rando, C., & Nakhaeizadeh, S.(2017). The Bias Snowball and the Bias Cascade Effects: Two Distinct Biases that May Impact Forensic Decision Making. J Forensic Sci. 2017;62(3):832-3. (Link to Reference)
2. Martin K, Ricciardelli R, Dror I. How forensic mental health nurses’ perspectives of their patients can bias healthcare: A qualitative review of nursing documentation. J Clin Nurs. 2020;29(13-14):2482-2494. (Link to Reference)