Different types of bias 3

Biases might emerge in assessments on which arguments or results are considered to be relevant for a particular logical or empirical claim. 

Notably, confirmation bias refers to the human tendency to consider only corroborating evidence instead of disconfirming evidence in the assessment of hypotheses. This bias might lead researchers to discount contrary evidence on methodological or substantive grounds, while corroborating evidence is accepted without much scrutiny. For instance, a biased review of the evidence of a set of studies might ignore the negative findings altogether, thereby creating an overly positive image of the robustness of a particular finding.

Personal bias might emerge when one person (e.g., a reviewer or a member of a grant or hiring committee) is assessing the qualities of (work of) another person, and this person has particular personal relations with that person (e.g., they are friends or close colleagues), which might create nepotism in academic contexts.  

Biases can also emerge in the assessment of persons from particular ethnic, demographic, professional, or social backgrounds, for instance when (works of) persons are judged based on social stereotypes (e.g., based on gender, ethnicity, nationality, or age) rather than on actual merit. Such personal biases are widely seen as unfair, and might be in violation of rules or laws relating to conflicts of interest or discrimination.