Research issues

• To accurately test the effects of the IV on the DV, you must control all other variables
• Extraneous variables are any variables other than the IV that might affect the DV if it's not controlled
• Participant variables refer to any characteristics or traits of the participants that might unfairly influence the results like age or personality.
• Investigator effects refer to any cues from an investigator (other than the IV) that encourage certain behaviours in the participant and might allow the researchers expectations to unfairly influence the results such as body language, bias and tone of voice.
• Environmental variables refer to any aspect of the research environment or situation (other than the IV) that might unfairly influence the results, such as heat, time of day and order effects
• Demand characteristics are any cues that reveal the aims of the study to the participants. If participants become aware of the aims their behaviour might change by trying to please the researcher to give them the results they want, try to ruin the experiment and the results, be more self-conscious as they are aware of the testing. This is an issue as it doesn't reflect real life. Examples include setting, procedure and rumours.
• What does PIED stand for to help remember all the extraneous variables


  Participant variables

  Investigator effects

  Environmental variables

  Demand characteristics
• There are key ways of controlling variables in research to ensure accurate results
• standardisation means putting in place "controls" to ensure that every aspect of the research is the same for all participants and meets a consistent "standard"
• standardisation includes using a standardised environment like a lab, that allows every aspect of the environment to be controlled. It also includes using standardised instructions like pre-recording what the researcher says to participants
• Randomisation means ensuring that all research "choices" are randomly selected by chance like using a number generator.
• random allocation ensures that there is no bias or preference when allocating participants into groups so that both groups have equal chances of being affected by co-founding variables
• the most common example of Randomisation is when using separate groups of participants in different experimental conditions, ensuring random allocation of participants to conditions and avoiding researcher bias.
• Co-founding variables are any extraneous variables that are not controlled and may have spoiled the results. This is because it is no longer clear if any change in the DV was caused by the IV or the co-founding variable.
• If there is a co-founding variable the results of the study are invalid