Experiments (Method + Design)

Question 1

what is the experimental method?

Answer 1

an experiment sets out to test a research aim and hypothesis.

Question 2

What is a true experiment?

Answer 2

a study of difference and is nomothetic. differs from non-experimental methods, involves deliberate manipulation of one variable while trying to keep all other variables constant.

Question 3

What is the IV?

Answer 3

Independent Variable- research manipulates

Question 4

What is the DV?

Answer 4

Dependent Variable- variable that is measured

Question 5

Characteristics of a true experiment

Answer 5

1. Researchers are looking for a different between conditions
2. Researcher look to manipulate the operationalised IV
3. Control (Extraneous Variables) and measure/record a change in the operationalised DV
4. Researchers will randomly allocate participants to each condition

Question 6

Types of experiments

Answer 6

-Laboratory Experiment
-Field Experiment
-Quasi Experiment
-Natural Experiment

Question 7

Experimental Designs include:

Answer 7

repeated measures, independent group, matched pairs

Question 8

What is the independent group design?

Answer 8

Different participants are placed in each condition. it is used to ensure that results are not influenced by order effects, to reduce the chance of demand characteristics and when repeated measured designs cannot be used

Question 9

Strengths of Independent group design:

Answer 9

-researchers only need to produce one set of stimulus materials
-order effects are reduced bc participants only experience one condition, increases validity
-reduces chance of demand characteristics

Question 10

Limitations of Independent group design:

Answer 10

-individual differences may confound the results
-more participants are required than in other designs, makes design expensive to use large sample size

Question 11

What happens in Repeated Measures Design?

Answer 11

Same participants are used in both conditions.
Used to reduce the influence of individual differences and where participants are difficult to sample

Question 12

Strengths of repeated measures design:

Answer 12

-individual results do not affect the results or any subsequent conclusions
-design is efficient; only one set of participant expenses

Question 13

Limitations of repeated measures design:

Answer 13

-participants experience both conditions so demand characteristics might confound the results
-at least 2 sets of stimulus materials are required
-increased chance of demand characteristics

Question 14

What happens in Matched pairs design?

Answer 14

different participants are used in each condition but they are matched on key variables to form pairs

Question 15

Strengths of matched pairs:

Answer 15

-researchers only need to produce one set of stimulus materials, reduces chances of confounding variables associated with the materials
-order effects are reduced bc participants only experience one condition- validity

Question 16

Limitations of matched pairs:

Answer 16

-matching pairs is difficult, time consuming and may be inaccurate/incomplete/invalid
-attrition might be an issue

Question 17

What is meant by operationalised?

Answer 17

when researchers operationalise variables, they express them in a form that can be measured accurately.

Question 18

What are extraneous variables?

Answer 18

EV are variables that might affect the results that haven’t been controlled.

Question 19

What are cofounding variables?

Answer 19

a variable that influences both the dependent variable and independent variable

Question 20

What is a Laboratory experiment?

Answer 20

Take place in lab
Independent variable is directly manipulated by researcher and effect on the dependent variable is measured
Extraneous variables controlled as much as possible

Question 21

Strengths of lab experiment:

Answer 21

-cause and effect can be inferred as isolation of effects of independent variable on dependent variable

• strict controls and well documented procedure: can replicate and check reliability of findings

-specialist equipment can deepen understand of behaviour

Question 22

Limitations of lab experiments:

Answer 22

-artificial context means participants do not demonstrate natural behaviour: reduces ecological validity

• demand characteristics are likely: may look to researcher for clues and adjust behaviour accordingly
• impossible to use in situations where would be inappropriate to manipulate IV for practical or ethical reasons

Question 23

What is a field experiment?

Answer 23

Same as lab experiment in the sense of IVs and DVs and EVs but lab experiment is swapped for real-life setting

Question 24

Strengths of field experiments:

Answer 24

-external (ecological) validity is higher than lab: can generalise findings to other settings

-demand characteristics are decreased compared to lab experiment: if participants are unaware they are taking part, they act naturally

Question 25

Limitations of field experiment:

Answer 25

• control of extraneous variables reduces in real world: reduce validity of results if lots

-if unaware they are taking part may get distressed: difficult to gain fully formed consent to debrief them

• researcher has no control over participants who take part, samples may be biased: population validity if reduced
  - opportunity sampling

Question 26

What is a quasi experiment?

Answer 26

Experiment with high degree of control of extraneous variables, researcher manipulated independent variable to find out it’s effect on dependent one.

Researcher is unable to freely manipulate the independent variable or randomly allocate participants to the two conditions

Question 27

Strengths and limitations of quasi experiment:

Answer 27

Similar strengths and weaknesses to lab experiment

BUT
no random allocation of participants- so participant variables more likely to confound the results compared to lab experiment

Question 28

What is a natural experiment?

Answer 28

No manipulation or control of any of the variables- naturally occurring

Question 29

Strengths of natural experiment:

Answer 29

-allow researchers to investigate topics that would be impractical and/or unethical to investigate using other methods

-ecological validity extremely high compared to lab. Able to study completely ‘real’ problems

-demand characteristics greatly reduced compared to lab experiment

Question 30

Limitations of natural experiments:

Answer 30

-no random allocation of participants: participant variable more likely to confound results

-researcher has no control over environment; extraneous variables reduced validity of results

-ethical guidelines are breached if unaware taking part in research (informed consent, confidentiality, right to withdraw)

-natural events to study are rare, often impossible to replicate research to test findings for reliability

Question 31

What is counter balancing (repeated measures design)

Answer 31

Used to over come order effects
- order of conditions is mixed up so half experience experimental condition then control and half the other way around

-although doesn’t eliminate order effects, mean any order effects are now equal across both conditions, so negative effect is reduced

Question 32

What is standardisation?

Answer 32

Process by which a researcher will establish a uniform procedure
-often achieved by developing written instructions to instruct participants what is expected of them