expectancy effects occur when data collectors or data coders influence the results of the research, usually to be more in line with their research hypotheses, while expectancy effect occur when participants respond "as they think they should"

Experimenter, participant

Explanation:

Experimenter expectancy effects can be described or considered as an error in the scientific findings or inquiries, where the researchers' expectations concerning their enquiries or findings are made known unconsciously to the subjects or participant, and this will automatically influence their responses.

This is also known as the object expectancy effect.

The subject or participant expectancy effect occurs when the result being expected by the participants or subjects unconsciously affect the expected result.

It should be noted that the experimental expectancy effect can be prevented by double-blind design. Double-blind design is a situation where both the experimenter and the participant do not know the subject identity.

The participant expectancy effect can be prevented by a single-blind design, where the subject is not aware if he/she is the experimental test object.