The Experimental Method Flashcards
What is the exp method?
- Involves the manipulation of an independent variable to measure effect on dependant variable
What are 3 main types of experiments?
1) Lab
2) Field
3) Quasi
What are the key components of the expansion method?
- Aims
- Hypotheses
- Variables (independant and dependant)
- Operationalisation
What is a lab study?
- Test of difference
- Carried out in controlled setting
(lab = term used to describe the environment where variables can be controlled) - Participants are often aware they are apart of a study
What are 2 strengths of lab studies?
Allow researchers to est. cause & effect
- Its possible to est. as the variables are very controlled so they know what thing changed has resulted in a particular behaviour
These studies give us a better understanding of human behaviour
Lab studies allow replicability
- Well carried out and all adjustments are recorded to ensure cause and effect
- Can be used by other researchers to obtain similar results and to increase validity of a study
What are 2 weaknesses of lad studies?
Lack ecological validity
- High control can reduce the real life feeling from experiments
- Involve artificial materials which makes it difficult to generalise these results to everyday settings
Tend to result in demand characteristics
- Participants are aware they are involved in a study and therefore may try to guess the aims and act accordingly
- The please you effect where the participant does what they believe is what the researcher is looking for
- Or behave in the screw you way and internally ruin the results
What is a field experiment?
- Conducted in a natural environment
- Field is anywhere outside a lab controlled environment
- IV and DV are still manipulated and measured
- Participants are not usually aware they are apart of an experiment
What is a strength of a field experiment?
Field exp are higher in ecological validity
- Participants are often unaware of being involved and art prone to demand characteristics
- findings are higher in ecological validity than they would be in a lab
What are 2 weaknesses of field exp?
Difficult to control extraneous variables
- Prone to be effected by extraneous variables
- It is impossible to control these variables in a field exp
- Difficult to est. cause and effect because of this (was it the IV or EV)
Difficult to replicate
- In lab study other researchers can confidently dictate what will and won’t happen
- Not possible to control EV in field experiment and cannot go back to the exact same place with the same exact settings
- Difficult to replicate and compare behaviours
What is a quasi exp?
- Exp that have an IV that is already existing and can’t be changed
- Age, gender, skin colour all cannot be changed as an IV they simply exist
What is 1 strength and 1 weakness of Quasi exp?
Can easily be controlled
- Conducted under same lab conditions
- Hold same strengths of a lab study
- The researcher can still change the IV and est. cause and effect
Extraneous variables still effect participants
- Most researchers will simple assume the unchanging IV is the only difference
- Other factors may contribute to effecting the DV like mood or personality
What is a natural experiment and what is an example of this?
-When the researcher observes the influence of a naturally occurring IV in a naturally occurring DV
-Conducted when not possible to deliberately manipulate an IV
e.g. Hodges and Tizard’s study of institutionalisation:
-unethical to separate newborns from parents to raise them in an institution to study effects
-they observed this naturally occurring phenomenon and its impact on later social development
-compared group of institutionalised to a similar ‘control group’ who weren’t raised in institution and monitored their social development:
-IV = whether raised in institution
-DV = various measures of social development
What are 2 strengths of a natural experiment?
Permit psychologists to explore difficult to access topics:
-Opportunities that may not otherwise be undertaken for practical or ethical reasons
-Known as ‘forbidden experiment’ due to impossibility of intentionally manipulating IV
-However the phenomenon occurs and the natural experiment technique allows us to explore effects
High in ecological validity:
-Behaviour that is measured is natural and not influenced by demand characteristics
-Makes it easier for researchers to confidently state their findings are representative of real-life behaviours
What is a limitation of natural experiments?
Researcher loses control over extraneous variables:
-No control over them - difficult to est cause and effect (can’t say for certain that the change in IV caused effect on DV)
