Control, Demand Characteristics and Investigator Effects

• What do researchers need to control/eliminate?

  extraneous variables
• How do we control/eliminate these variables?

  by random allocation, counterbalancing, randomisation, standardisation
• What is random allocation good for?

  It greatly decreases the possibility that participant variables in the form of individual differences will adversely affect the results
• What is counterbalancing good for?

  Combats the problem of order effects with repeated measures design. The sample is split in half with one half completing the two conditions in one order and the other half completing it in the reverse order. Any order effects will be balanced out by the opposing half of P's
• What is randomisation


  When trials are presented in a random order to avoid any bias that the order of the trials might present
• What is standardisation 


  When all situational variables of a procedure used in research are kept identical so that methods are sensitive to any change in performance. Means the results will more likely be replicated because the research is standardised
• What are demand characteristics 


  These occur when the participants try to make sense of the research and change their behaviour accordingly to support what they believe are the aims of the investigation.
• Investigator effects 


  then the researcher acts in a way to support their prediction.