Control Of Variables Flashcards
Operationalise confidence levels.
1-5 scale
What does Extraneous Variable mean?
- Any variable that isn’t IV that affects DV and doesn’t systematically vary with IV - nuisance variables
- E.g. age of participant
What should happen to any variables that affect DV other than IV?
It should be:
- Removed from the experiment
- Be well controlled
What is a Confounding Variable?
- Any variable that isn’t IV which affects DV and systematically varies with IV
- It’s hard to be sure of origin of impact of DV
- E.g. time a task is done
What are Demand Characteristics?
Any cue the researcher/reasearch situation may give which makes participant feel like they can guess aim of investigation
What can Demand Characteristics cause?
- Can lead to participant change behaviour consciously/unsconsciously to try and fit situation
- Please-U
- Screw-U
What are Investigator Effects?
Any unwanted influence from researcher’s behaviour, conscious or unconscious, on DV measured
Give examples of Investigator Effect.
[3]
- Design of study
- Selection of participants
- Interaction with each participant during research investigation
What two things can be used to minimise effect of extraneous/confounding variables?
- Standardisation
- Randomisation
What is Standardisation?
- Using the exact same formalise procedures and instructions for every single participant involved in research process
- Can reduce extraneous and other unwanted variables
What is Randomisation?
- The use of chance to reduce the effect of bias from investigator effects
- E.g. when designing materials
What is a Single Blind Procedure? What does it reduce?
[3]
- Where only researcher know who is who in an experiment
- Participants don’t know
- Reduces demand characteristics
What is Double Blind Procedure?
[2]
- When participant and researchers don’t know conditions
- Reduces demand characteristics and investigator effects
