Identify the problems associated with observer bias and observer drift. How can researchers identify and overcome these problems?

What will be an ideal response?

Observer bias involves the researcher bring his or her predispositions to the observations, inadvertently recording those behaviors that reinforce beliefs or expectations and ignoring behaviors counter to expectation. This problems can be overcome, in part, through the use of a behavior checklist with objective definitions of behaviors to be coded.
Observer drift involves changes in observational criteria by a researcher over the course of a study. As a result, the same behavior can lead to different responses at different points in the study. Researchers can minimize the effects of observer drift by (a) using objective criteria, (b) systematic training of observers, (c) retraining observers and changing pairs of observers so the same people don't always work together. Researchers can check on consistency of observations by looking at interobserver reliability.