Observer Bias

Observer bias is quite similar to demand characteristics except that the bias is with the "observers" of the research (i.e., the research team) rather than the participants. In other words, observer bias occurs when the observers (or researcher team) know the goals of the study or the hypotheses and allow this knowledge to influence their observations during the study. For example, if an observer knows that the researcher hypothesized that females speak in more complex sentences, they may believe they hear females speaking that way during the study even if it's not really true.