The process where participants may change their behaviour during the experiment as they have guessed the aim
also referred to as 'participant reactivity'
considered a type of extraneous variable
Hawthorne effect
Guessing the purpose of the experiment and trying to please the researcher by over-performing
'Screw you' effect
Guessing the purpose of the experiment and giving the wrong answers to try and annoy the researcher
Social desirability
Acting unnaturally as you're worried how you will be perceived
Investigator effects
This refers to the researcher's features and how they might affect the participant's response - physical characteristics, leading questions, unconscious bias in their interpretation of results
can be reduced by using double-bind procedure
Double bind procedure
Neither the researcher or the participant knows which condition of the experiment they are taking part in
Single-blind procedure
Where there are two conditions of the independent variable and the participant will not know which condition they are participating in
Randomisation
The use of methods to reduce the researcher'sunconscious biases when designing an investigation
e.g. randomly deciding on order of conditions within experiment using a random generator
Standardisation
Researcher should use standardised procedures and instructions (which is when the procedures are the exact same for all PPs involved) so the study is fair and holds everybody to the same standard, increasing the validity.
