Experimental Design

Question 1

Define Random Allocation.

Answer 1

An attempt to control for pps variables in an independent groups design ensuring that each pps has the same chance of being in one condition as any other

Question 2

Define Counterbalancing.

Answer 2

An attempt to control for the effects of order in a related measures design:half the pps experience the conditions in one order and other half in opposite order

Question 3

Define Experimental Design.

Answer 3

The difference in which pps can be organised in relation to the experimental conditions
-Is really the ‘way’ pps are used

Question 4

What are the 3 types of experimental design?

Answer 4

-Independent Groups
-Repeated Measures
-Matched Pairs

Question 5

What is an Independent Group Design?

Answer 5

Where pps are allocated to different groups where each group represents on experimental condition

Question 6

What happens in an Independent Group Design?

Answer 6

Performance of two groups are compared
-if there are two levels of independent variable, all pps would only experience one

Question 7

What is a Repeated Measures Design?

Answer 7

Where all pps take part in all conditions of the experiment
-experience each condition in same order

Question 8

How are the results from Repeated Measures Design concluded?

Answer 8

The two mean scores of both conditions would be compared to see is there was a difference

Question 9

What is a Matched Pairs Design?

Answer 9

Where the pairs of pps are first matched on some variables that affect the dependent variables. One member of the pair is then assigned to each condition.

Question 10

What is the purpose of a matched pair design?

Answer 10

An attempt to control the confounding variable of participant variables and often necessities the use of a pre-test if matching is to be effective.

Question 11

How would the experiment then be run?

Answer 11

In the same way as an independent group design

Question 12

What is the first advantage of using repeated measures?

Answer 12

No participant variables so there won’t be any individual differences between the participants in each condition-increases internal validity

Question 13

What is the second advantage of using repeated measures?

Answer 13

Requires half the number of participants as other designs so don’t have to recruit as many participants so it is cheaper and less time-consuming

Question 14

What is the first disadvantage of using repeated measures?

Answer 14

Suffers from order effects which may affect pps performance so counterbalancing is done to deal with this

Question 15

What is the second disadvantage of using repeated measures?

Answer 15

High demand characteristics so pps have a higher chance of guessing the aim of the experiment which could effect their behaviour

Question 16

What is the first advantage of using independent groups?

Answer 16

No order effects so doesn’t affect pps performance

Question 17

What is the second advantage of using independent groups?

Answer 17

Low demand characteristics so pps have less chance of guessing the aim of the experiment

Question 18

What is the first disadvantage of using independent groups?

Answer 18

Low degree of control over participants variables so may be individual differences between pps in each condition impacting the results

Question 19

What is the second disadvantage using independent groups?

Answer 19

Requires twice as many participants as a repeated measure meaning it’s more expensive and very time-consuming

Question 20

What is the first advantage of using a matched pair design?

Answer 20

No order effects so doesn’t affect pps performance

Question 21

What is the second advantage of using a matched pair design?

Answer 21

Low demand characteristics so pps have less chance of guessing the aim of the experiment

Question 22

What is the first disadvantage of using a matched pair design?

Answer 22

Less control of participant variables than repeated measures design so there is still a change of individual differences which could influence and confound the results

Question 23

What is the second disadvantage of using a matched pair design?

Answer 23

Requires twice as many participants as a repeated measure meaning it’s more expensive and very time-consuming