Experimental Method

Question 1

What are the 4 types of experiments?

Answer 1

• Laboratory
• Field
• Natural
• Quasi

Question 2

Independent Variable

Answer 2

• What the researcher manipulates.

- Assumed the IV will have a direct effect on the DV

Question 3

Dependent Variable

Answer 3

• What the researcher measures (the change in behaviour)

- Look at how behaviours change as a result of the manipulation of the IV.

Question 4

Extraneous Variables

Answer 4

• Any variables other than the IV that might affect the DV

Question 5

Confounding Variables

Answer 5

• Extraneous variables that cannot be controlled

Question 6

2 advantages of the Experimental method

Answer 6

• Easy to replicate due to the high level of control
  > Others can carry out the experiment to check the reliability of the results
• Causal relationships can be inferred
  > Changes in dependent variable are due to changes in the independent variable.

Question 7

2 disadvantages of Experimental method

Answer 7

• Low Ecological validity
  > Findings cannot be generalised to real life situations
• Demand Characteristics
  > Change behaviour if they know the aim of the study

Question 8

Operationalise

Answer 8

• Operationalisation means to ‘make testable’.

- We operationalise our IV and DV in order to make it testable

Question 9

Laboratory Experiments

Answer 9

• Scientific method

> Highest level of control over all variables

Question 10

2 advantages of Laboratory experiments

Answer 10

• Easy to replicate
  > Easy to test the reliability of the original findings.
• High degree of control
  > Easy to assume that changes in the DV are due to changes in the IV.

Question 11

2 disadvantages of Laboratory experiments

Answer 11

• Low Ecological Validity
  > Difficult to generalise the findings to real world situations (Artificial study)
• Demand characteristics
  > Participants may change their behaviour

Question 12

Field Experiments

Answer 12

• Carried out in the participants’ natural environment

> Measuring behaviour in the location in which it would normally occur.

Question 13

2 advantages of Field experiments

Answer 13

• High ecological validity
  > Conducted in the participants’ own environment (participants are acting as they normally would)
• Less chance of demand characteristics
  > Often unaware they are taking part in a study (unlikely to change their behaviours)

Question 14

2 disadvantages of Field experiments

Answer 14

• Less control Researchers
  > Cause and effect relationship between IV and the DV is not as strong
• Potential ethical issues
  > Participants don’t know that they are taking part in the study

Question 15

Natural Experiments

Answer 15

• IV is not directly manipulated by the researcher

- Naturally occurring

Question 16

2 advantages of Natural experiments

Answer 16

• High ecological validity
  > Participants acting naturally, happens to be researchers to measure their behaviours.
• It allows the study of sensitive issues
  > Involve an IV that would be unethical to manipulate

Question 17

2 disadvantages of Natural experiments

Answer 17

• Difficult to replicate
  > Changes in the IV are ‘one offs’- reliability cannot be tested through replication.
• Lack of control
  > IV is not being directly manipulated by the researchers

Question 18

Quasi Experiment

Answer 18

• IV which forms part of the participant
  > (e.g. their age, gender or personality type)
• Participants cannot be randomly allocated to conditions

Question 19

2 advantages of Quasi experiments

Answer 19

• High degree of control
  > Carried out in the same controlled conditions as laboratory experiments
• Replicable
  > When the IV is straightforward easy to repeat the study

Question 20

2 disadvantages of Quasi experiments

Answer 20

• Random allocation to conditions not possible
  > This means that by chance the two conditions could differ on a variable that might affect the DV
• Difficult to find a sample if condition of the IV is rare
  > Hard to recruit the required number

Question 21

What are the 2 types of extraneous variables?

Answer 21

• Situational Variables

- Participant Variables

Question 22

Situational Variables

Answer 22

• Variables connected with the research situation
  > eg. temperature, instructions, time of day, lighting and materials used in the investigation are all situational variables.
• Controlled through standardisation
  > Ensuring that the only thing that differs between the two conditions is the IV
• Standardised instructions - ‘set instructions’ that should be read to all participants
• Standardised procedures - Detailed instructions as to how the research should be carried ou

Question 23

Participant Variables

Answer 23

• Variables connected with the research participants
  > eg. intelligence, age, gender and personality
• Controlled through the experimental design eg. matched pairs
  > Random allocation - control participant variables by reducing bias