Experimental design

Question 1

what is a repeated measures design and list strengths and how to deal with any issues

Answer 1

all participants receive all levels of the IV
the order of conditioning may affect performance
When participants do the second test they may guess the aim of the experiment
Participant variables are eliminated as the same participant is used twice. They are kept consistent
Researchers may use two different tests to reduce practice effect or to deal with order effects they may use counterbalancing - ensures that each condition is tested first or used in equal amounts

Question 2

How would you use counterbalancing in an experiment

Answer 2

AB or BA
- condition one: each participant does A then B
- condition two: each participant does B then A
ABBA
- trial one: condition A (morning)
- trial two: condition B (afternoon)
- trial three: condition B (afternoon)
- trial four: condition A (morning
Then we compare scores on trial one with four and trials 2 with three

Question 3

what is independent groups design, what are the evaluations and what are the methods to deal with this

Answer 3

Participants are placed in separate groups, each participants does one condition or level of the IV
Reduces demand characteristics because participants only take part in one condition unable to pick up on cues (high internal validity)
requires more participants which means research is more expensive to carry out
Use random allocation to distribute participant variables evenly

Question 4

What are matched pairs designs and what are the evaluations and how do you deal with any problems

Answer 4

Participants take part in only one condition but they are matched in terms of shared characteristics i.e age
Reduces demand characteristics, participants take part in one condition so they are less likely to pick up on cues
Requires twice the number of participants which is more expensive
Restrict the number of variables
Conduct a pilot study to consider key variables that might be important when matching