Experimental Methods

Question 1

What is a Lab experiment?

Answer 1

Experiment conducted in a lab which is a highly controlled environment

Researcher manipulates the IV and measures the effect on the DV

Question 2

Lab experiment strength

Answer 2

High level of control over extrnuous variables

Thus cause and effect can be established between IV and Dv
Increasing internal validity

Question 3

Lab experiment limitation

Answer 3

Lacks ecological validity as its carried out in artificial environment

Difficult to generalise findings IRL

Lowering external validity

Question 4

What is a field experiment ?

Answer 4

Takes place in a natural environment such as office or school

Researcher manipulates the IV and measure the effect on the DV

Question 5

Field experiment strength

Answer 5

High ecological validity , based irl setting thus easier to generalise findings beyond setting of the study , to other similar settings

Question 6

Field experiment limitation

Answer 6

Low reliability , as environment
is natural it’s difficult to repeat with exact same conditions

To check for consistent results

Question 7

What is a natural experiment ?

Answer 7

Researcher takes advantage of naturally occurring IV (event )

variable would change even if experimenter was not interested

Iv is natural not necessarily the setting

Ppts may be tested in a lab

Question 8

Natural experiment strength

Answer 8

Provide opportunities for research that may not otherwise be undertaken, for practical and ethical reasons

Eg rutters study on Romanians orphans would have been unethical to manipulate unless institutionalisation (IV) had not yet occurred naturally

Natural experiments contribute to a greater psychological understanding of behaviour

Question 9

Natural experiment limitation

Answer 9

Low control over extraneous variables as natural experiments usually take place in a natural environment

Difficulty to establish cause and effect

Question 10

What is a quasi experiment ?

Answer 10

Iv based on existing individual differences between people

Which the researched has not manipulated eg age or gender

Question 11

Quasi experiment strength

Answer 11

Can be conducted in natural field or lab so you write an evaluation based on the scenario

Question 12

Quasi experiment limitation

Answer 12

Sample bias as they may have unique characteristics

Difficult to generalise to target population

Decreasing external validity of study

Question 13

Independent groups

Answer 13

There is one condition with diffrent ppts

Question 14

Advantage of independent groups

Answer 14

No order effects as ppts take place in one condition will not get bored or tired

Question 15

Disadvantage of independent groups

Answer 15

Individual differences (extraneous variables ) eg some ppts may have better memory

Question 16

Repeated measures

Answer 16

Ppts take place in all conditions of experiment

Question 17

Advantage of repeated measures

Answer 17

Individual differences removed as all ppts are in all conditions

Question 18

Disadvantage of repeated measures

Answer 18

Order effects ppts take place in one or more experimental conditions they may perform worse or better

Question 19

Matched pairs

Answer 19

Ppts are matched in characteristics in the study eg age or IQ

Question 20

Advantage of matched pairs

Answer 20

Reduces individual difference between ppts

As it matches ppts on variables important to the research

Researcher can be sure that changes in DV are due to iv

Question 21

Disadvantage of matched pairs

Answer 21

Indivudual differences cannot be fully
Eliminated

Not able to match ppts based on all variables

Thus this could question the validity of the matched pairs

Unlike RM where each condition will use same ppts thus individual differences eliminated

Question 22

How can order effects be solved ?

Answer 22

Do half of the participants in condition A to B and half the participants in condition B to A

Question 23

How can individual differences be solved ?

Answer 23

Random allocation

All people names on equal size paper

Put into a hat

Remove how may needed