The experimental method

Page 1

Psychologists believe human behaviour should be measured in scientific settings

Procedures are used

Most common method is the experiment

An idea is formed.

A hypothesis is written

Variables are considered...what will be tested and what will be manipulated to see the effect

Conditions (usually 2) are decided upon

Design is considered

Page 2

There are 3 designs

Independent groups

Repeated measures

Matched pairs

Independent groups

Group A does condition A

Group B does condition B

Advantages

No order effects

Same material can be used for the task in both conditions

Participants cannot work out the aim

Disadvantages

There are different people in each condition (participant variables)

20 people are needed if 10 wanted for each group

Page 3

Repeated measures

One group of participants

This group does condition A and condition B

Advantages

No participant variables

Only need 10 people not 20

Disadvantages

There are order effects as all participants do the test in condition A AND B

Two tasks and set of materials might be needed

They might work out what is happening

Page 4

Page 5

Matched pairs

Participants are tested and matched to someone with similar IQ, gender e.t.c.

Then the pair is split into Group A and Group B

Group A does condition A and Group B does condition B

Twins can be a matched pair

Advantages

Participant variables are reduced

No order effects

Same material can be used

Disadvantages

Matching is difficult and time consuming and not always successful

Some participant variables remain

Sample needs to be huge to get the required 10 per condition