EXPERIMENTAL DESIGNS

Question 1

What is an experimental design?

Answer 1

Experimental design is the method in psychology is the conditions in which the experiment includes and which participants are allocated to different groups/conditions of an experiment.
What the experimental conditions are as well as how and which participants are allocated to them.

Question 2

Describe and Evaluate independent groups design

Answer 2

Independent groups design
Participants are divided into groups and each group only does one (Is allocated to only one) experimental condition
Strength-
* Participants are less likely to guess experiment aims, reduced demand characteristics
* Avoids unconscious bias by researcher, especially if random allocation is used
Limitations-
* Individual differences may have an effect
* May need larger sample/ more participants and gathering of sample may be more time consuming

Question 3

Describe and evaluate repeated measures design

Answer 3

Repeated measures design-Participants take part in all conditions of the experiment
Strengths-
* Resolves problem of individual differences as participants take part in all conditions
* Lower sample amount needed, gathering may be less time consuming
Weaknesses-
* Increased chance of demand characteristics (Can control this by using single blind)
* Order effects are more likely (Fatigue and practice) - Performance in one condition is influenced by previous condition of experiment
* Can resolve order effects using counterbalancing (ABBA) having participants do conditions in different order

Question 4

Describe and Evaluate matched pairs design

Answer 4

Matched pairs design

Different participants are assigned to different conditions of experiment, matched on characteristics important/ in relation to study, normally found by pre-testing and/or researching participants backgrounds/lives.
Participants in pairs either only do A or only do B.

Strengths-
* Conditions can be more reliably compared, causation more easily established
* Reduced individual differences
Weaknesses-
* Time-consuming,
* Many participants may be excluded from study due to not meeting matching criteria such as characteristics.