research issues

• extraneous variable 


  • Any additional/unwanted variables that can potentially affect the independent variable which results in effects to the dependent variable.
  • These variables must be controlled, removed and identified at the start of the study by the researcher
• participant variables 


  • differences between participants
  • Examples: gender, IQ, age
• researcher variables 


  • factors such as researcher behaviour
  • Example: gender and appearance
• situational variables 


  • the researcher should control of the setting where the experiment takes pace.
  • Examples: keeping light, sound and temperature levels consistent.
• demand characteristics 


  • when ppts change their natural behaviour after guessing the aims of the study
  • this affects how they respond in any tasks tehy are set
  • reduces validity
• types of demand characteristics

  please you effect

  screw you effect

  social desirability bias
• please you effect 


  ppts may try to please the researcher by doing what they have guessed is expected of them
• screw you effect 


  ppts may deliberately try to skew the results in one way or another, attempting to do the opposite of what they think is expected.
• social desirability bias 


  the bias ppts behaviour occurs hen they realise aspects of the study are about social norms and expectations, and in turn present themselves in a social acceptable way.
• Investigator effects 


  Occurs when a researcher unconsciously influences the outcome of any research they are conducting.

  • non verbal communication
  • physical characteristics
  • bias interpretation of data
• bias interpretation of data

  a researcher can affect the results reported from a piece of research by interpreting the data in a biased way.
• physical characteristics 


  the appearance of the researcher will influence the behavioural response of the participant.
• non-verbal communication 


  An action committed by the researcher can make the ppt aware that they may have said or done something that has surprised them and they may alter their response as a consequence of this.

  • reduces validity
• dealing with research issues

  • randomisation
  • standardisation
  • single-blind procedure
  • double-blind procedure
• randomisation 


  the use of chance methods to reduce the researcher's unconscious biases when designing an investigation
• Standardisation


  using the same procedure and instructions for each participant in a study.
• single-blind procedure 


  participants are not told the aim of the study/ other details may be kept from the participants

  • reduces demand characteristics
• double-blind procedure 


  Neither the participant or the researcher is aware of the aims of the investigation. A 3rd party conducts the investigation w/o knowing its main purpose.

  • reduces demand characteristics
  • reduces investigator effects
• co-founding variables

  • a variable that has had an effect on the dependent variable
  • we cannot tell if any change to the DV is due t the IV or the cofounding variable
  • has had an effect