Week 5-Experimental Designs and Observation Methods Flashcards
(45 cards)
Define Between-Subjects Design
■Groups are made up of different people
■Measures difference in performance between subjects (groups).
Give 2 disadvantages to Between-Subjects Design
1.Large no. of participants required
2.Participant characteristics and variables (individual differences).
E.g., Gender, age, personality, IQ, family background, level of education, etc.
Define Confounding Variables
Extraneous variable that influences the results of the study e.g., situational variables
■Have to think of constancy in Conditions
Give 3 examples of situational variables
1.Environment
2.Room temperature
3.Time of day
Give an example of expectancy effects
When someone expects a given result, that expectation unconsciously affects the outcome or report of the expected result
E.g.:
–P’s may expect exercise not to affect their weight gain
–Constancy:keep P’s naïve to the true aim of the study
–Effect not caused by expectancy.
State 3 main between-subjects designs used in balancing and matching participant characteristics/variables
Random allocation design
Matched group design
Natural groups design
Explain Random Allocation Design
–P’s randomly assigned to conditions (groups)
–Controls for participant variables:
Age, gender, occupation, IQ, smokers etc.
–Sample size in all conditions should be similar
Explain Matched Group Design
Matching participants in each group based on a certain characteristic. E.g. Gender, IQ, age, political orientation, ethnicity, smoker/non-smoker, level of education etc.
Define Within-Subjects Design
Repeatedly measuring the same people on the same DV.
Give disadvantages of Within-Subjects Design
1.Boredom/fatigue
2.Practice (Order) effects:
Learning
Fatigue
Habituation
Sensitisation
Contrast
Adaptation
What’s Incomplete Within-Subjects Design?
■Each condition was administered to each participant once.
■Order of administration varied across participants.
■Practice effects balanced across individuals.
What 2 main counter-balancing methods are used to prevent practice effects in incomplete within-subjects design?
1.Do all the possible orders. (levels of IV=number of orders/groups needed 2=2x1=2 3=3x2x1=6 etc.)
2.Selected orders. (Latin square design and each condition occurs once in each position.):
■Each condition precedes and follows each other condition only once.
Explain Complete Within-Subjects Design
■Each condition administered several times - different orders each time.
■Practice effects balanced for each participant.
Give the 2 main counter-balancing methods used in complete within-subjects design
1.Block Randomisation.
2.The ABBA design.
Explain Block Randomisation
■A block consists of all conditions.
■P’s complete the condition several times, each time in a different order:
Block 1 Block 2 Block 3
HFSN - SNFH - FHNS etc.
Every participant does all possible orders.
Explain The ABBA design
■Present one random sequence of conditions (e.g. FSHN).
■Then present the opposite sequence (NHSF).
■Each condition has the same amount of practice effects.
■If there are only 2 levels of the IV then present them in one order and then the other several times
Give an example showing the differences between Incomplete vs. Complete design
■Incomplete: either HIT then No activity or No activity then HIT NOT BOTH
■Complete: HIT then No activity and No activity then HIT. BOTH
Give 5 Limitations of the Within-Subjects Design
■Individual differences (e.g. gender, IQ)
■Time-consuming conditions
■Levels of the IV represent an unfolding time sequence that can’t be undone
■The task (DV) can’t be repeated
■Differential transfer between conditions
Define Differential Transfer
Effects of one condition affect performance in subsequent conditions.
E.g. Test on the same day in each condition:
Neutral Words – Frightening Words = No transfer
Frightening Words – Neutral Words = Transfer
What are 2 ways to avoid the transfer effect?
1.Between-subjects design
2.Within-subjects design with each condition sufficiently spaced
Define Observational Methods
■Study of animals and people within a natural environment.
■Used if practical and moral considerations mean no control of
variables.
Explain Observation Without
Intervention: Naturalistic observation
■Behaviour as it occurs naturally without intervention
■Passive recorder of behaviour
■Can be overt/ covert
Give 3 famous animal observational studies
1.Charles Darwin’s voyage on HMS Beagle.
2.Jane Goodall’s study of chimpanzees.
3.Diane Fossey’s study of mountain gorillas.
Give 4 advantages of Observation Without Intervention
■Behaviour in the real world
■High external validity
■Study complex social situations
■Developing theories.
