Experimental Designs

Question 1

Name three experimental designs

Answer 1

Independent groups
Repeated measures
Matched pairs

Question 2

What is independent group designs?

Answer 2

Ppts take part in one condition. Each condition has different group of ppts.

Question 3

How to conduct independent group design?

Answer 3

-group of ppt recruited
- split into equal sized groups
-different group allocated to each condition

Question 4

What are two advantages of independent groups design?

Answer 4

No order effects
Can be used when repeated measures design is inappropriate

Question 5

Why is no order effects a strength of independent groups design?

Answer 5

Ppts only take part in one condition so they don’t get bored/fatigued or better at the task/have lasting effects from one condition to the next UNLIKE repeated measures design where ppts take part in all conditions and could have order effects

Question 6

What are order effects?

Answer 6

Ppts get bored/ tired or better/ worse at a task when they take part in more than one experimental condition

Question 7

What experimental design has no order effects?

Answer 7

Independent groups design

Question 8

Independent groups design can be used when….

Answer 8

Repeated measures design is inappropriate as each condition needs to be different

Question 9

What are two disadvantages for independent groups design?

Answer 9

Individual differences
More ppts are needed

Question 10

Why are individual differences a limitation for independent groups design?

Answer 10

As they might affect the DV as there are separate groups of ppts in each condition (e.g some ppts may have better memory which wouldn’t be suitable in a memory study) lowering the internal validity UNLIKE repeated measures that used the same group of individuals in all conditions to reduce the effect of individual difference

Question 11

Independent groups design is limited by ….as they might affect the … as there are …. groups of ppts in each … (e.g some ppts may have better memory which wouldn’t be suitable in a memory study) lowering the …. validity UNLIKE …. measures that used the …. group of individuals in …. conditions to ….the effect of individual difference

Answer 11

Individual differences
DV
Separate
Condition
Internal
Repeated
Same
All
Reduce

Question 12

Why is more ppts being used in independent groups design a limitation ?

Answer 12

More ppts are needed as two different groups are required for the different conditions UNLIKE repeated measures where you use less ppts as every ppt take part in all conditions

Question 13

Define repeated measures

Answer 13

All ppts take part in both conditions of the experiment. Same ppts used in all conditions

Question 14

How do you conducted a repeated measures design?

Answer 14

-ppts complete one condition
-after time delay they will complete the next condition
-the task should be different but matched in difficulty/measuring the same thing

Question 15

What are two advantages to repeated measure design?

Answer 15

Individual differences
Requires fewer ppts

Question 16

Why is individual differences an advantage to repeated measures design?

Answer 16

Individual differences between ppts in each condition are removed (e.g IQ has potential confounding variable as same ppts take part in all conditions) therefore the researcher can be more sure that any changes in the DV are due to the IV and not any other variable increasing the internal validity UNLIKE IGD that will sue different ppts in different conditions so individual differences could effect the DV

Question 17

Why is repeated measure using fewer ppts an advantage ?

Answer 17

Requires fewer ppts as ppts take part in all conditions UNLIKE in IGD as depart groups are needed for separate conditions

Question 18

Give two disadvantages for repeated measures design

Answer 18

Order effects
Increase in demand characteristics

Question 19

Why are order effects a limitation to repeated measure design?

Answer 19

Order effects may take place when ppts take part in more than one experimental condition. They may perform worse in one condition due to boredom/fatigue, or better in the second condition due to practice, or there may be lasting effects from condition 1 to 2 lowering the internal validity UNLIKE IGD where ppts only take part in one condition so cannot be susceptible to order effects

Question 20

When do order effects take place?

Answer 20

When ppts take place in more than one experimental condition

Question 21

What does order effects lower?

Answer 21

Internal validity

Question 22

Why is increased demand characteristics a limitation of repeated measures?

Answer 22

Bc ppts take part in all conditions. They may take pick up on clues given off by researcher as they spend much more time with them and change their natural behavior to help or hinder the research lowering the internal validity UNLIKE IGD where ppts are less likely to pick up on clues as they only take part in one condition of the research

Question 23

Describe matched pairs

Answer 23

Ppts are matched on important characteristics in the study e.g age or IQ. By giving them an appropriate test and matching two ppts with the same score. Each member of pair is randomly allocated across each condition

Question 24

How do you conduct match pairs

Answer 24

-choose variable to match ppts on
-test the ppt on this variable before the study
-match ppt with same scores
-randomly allocate each member of the pro to one condition

Question 25

What are two strengths is matched pairs?

Answer 25

Reduced individual differences
No order effects

Question 26

Why is reduced individual differences an advantage of matched pairs?

Answer 26

As it matched ppts based on variables important to the research such as age/IQ/happiness. Therefor the researcher can be more sure that any change in the DV are due to the IV and not an other variable. UNLIKE in IGD where separate ppts are in separate conditions

Question 27

Matched pairs has reduced … as it matched ppts based on …….such as age/IQ/happiness. Therefore the researcher can be more sure that any change in the … are due to the …. and not an other variable. UNLIKE in IGD where separate ppts are in separate conditions

Answer 27

Individual differences
Variables important to the research
DV
IV

Question 28

Why is there no order effects in matched pairs, why’s it an advantage?

Answer 28

Bc ppts only take part in one condition so they will not get bored/fatigued or better at the task/have lasting effects from one condition to another UNLIKE RMD where ppts take part in all conditions and could have order effects

Question 29

Give limitations to matched pairs

Answer 29

Time consuming
Individual differences cannot be fully eliminated

Question 30

Why is matched pairs limited by it being time consuming?

Answer 30

Time consuming to match up and find similar participants especially if a pre-test is needed to match ppts on certain characteristics. Psychologists would need a very large pool of ppl UNLIKE RMD where the same ppts are used through all conditions.

Question 31

Match pairs is ….to …. up and find …. participants especially if a…. is needed to match ppts on certain …. Psychologists would need a very … pool of ppl UNLIKE RMD where the same ppts are used through all conditions.

Answer 31

Time consuming
Match
Similar
Pretest
Characteristics

Question 32

Why can individual differences not be fully eliminated in matched pairs designs?

Answer 32

Bc psychologists match ppts on variables important for the research but are not able to match ppts on all the variables. Therefore this could question the validity of the matched pairs design. UNLIKE RMD where each condition will use same ppts therefore individual differences are eliminated