The Observer-Expectancy Effect is where a researcher’s own biases causes them to subconsciously influence the participants of an experiment or research project. This is a type of confirmation bias which can lead to the experimenter interpreting results incorrectly because of the tendency to look for information that conforms to their hypothesis and overlook information that argues against it.
One useful counter-measure is to ask yourself: What thoughts, feelings or actions am I processing that could influence the participants or the results of this activity? How can I limit the influence effectively?
For a full list of the most common biases, click here.