How might experimenter bias manifest when grading subjective data?

Answer

Subconsciously interpreting ambiguous observations in a way that favors their hypothesis

In subjective recording, experimenter bias manifests when a researcher unconsciously interprets ambiguous observations, such as borderline essay grades, in a manner that supports their pre-existing hypothesis regarding the treatment's effectiveness.

How might experimenter bias manifest when grading subjective data?
influenceexperimentbiasoutcome