Investigator Effects

Investigator effects occur when a researcher unintentionally, or unconsciously influences the outcome of any research they are conducting.

This can be done in several ways

1 Non-verbal communication

The researcher can communicate their feelings about what they are observing without realising that they have done so. For example, a raised eyebrow can make the participant aware they may have said or done something which has surprised or shocked a researcher and they may alter their response as a consequence of this, affecting the validity of the data.

2. Physical characteristics

The appearance of the researcher and such physical characteristics as their gender will influence the behavioural response of the participant. This means that the behaviour is a product of the situation because of the researcher and therefore may not be reliable or valid.

3. Bias in interpretation of data

A researcher can affect the results reported from a piece of research by interpreting the data in a biased way. They may not realise that they are interpreting it in a different way to someone else because it feels as if their view is the correct one. The extent to which this can occur is dependent on the data collected. This would not occur if the dependent variable is something like reaction time as this is an objective method of measurement.