Research Methods- Types Of Experiment

Question 1

Laboratory Experiments:

Answer 1

Defined by the high level of control the researcher has over all the variables in the study.

Question 2

In laboratory experiments what does the experimenter control?

Answer 2

The experimenter will control environmental factors e.g. noise and temperature as well as the experience each participant has by using standardised procedures.

Question 3

Variables in laboratory experiments:

Answer 3

The independent variable (IV) is changed (manipulated) by the researcher between the conditions of the experiment. Any change in the dependant variable (DV) will be measured while all other possible variables that could change the DV are kept consistent between conditions.

Question 4

Evaluation
Laboratory experiments
✅

Answer 4

• By holding all variables outside of the IV and DV consistent researchers can be confidant in establishing a cause and effect relationship between changes/manipulations in the IV and the observed difference in the DV.

• High internal validity, meaning observed change in DV is due to change in IV.

• Lab studies are easily replicated due to the use of standardised procedures.

Question 5

Evaluation
Laboratory experiments
❌

Answer 5

• Lab studies can lack ecological validity, a type of external validity. This means
findings from a lab study cannot be applied to a range of real-world situations

• Tasks conducted in lab studies often don’t reflect the kind of tasks performed in real-world situations (they lack mundane realism) lowering external validity

• Participants are aware they are in a study, they may alter their behaviour due to demand characteristics, changing behaviour to match the aim.

Question 6

Field experiment

Answer 6

Defined by conducting the experiment in naturalistic settings. This change in location is an attempt to avoid the artificial nature of lab studies.

Question 7

Locations field studies are conducted in can include…

Answer 7

shops, work and school, or anywhere the participants would be expected to. behave naturally.

Question 8

Variables in field experiments

Answer 8

Independent variable (IV) is still changed by the researcher between the conditions of the experiment and the researcher then measures the difference in the dependant variable (DV)

Question 9

Field experiments
Evaluation
✅

Answer 9

• Participants should behave more naturally in their normal environment, making it more likely any behaviour observed in the field experiment can be applied to other naturalistic settings. (higher ecological validity)

• Tasks used in field experiments are more likely to have mundane realism, so be closer to the type of activities that the participant usually carries out.

• If participants are unaware they are in an experiment participants will not show demand characteristics.

Question 10

Field experiments
Evaluation
❌

Answer 10

• Field studies lack control over possible extraneous variables that could be influencing the measurement of the dependant variable.

• In many field studies, it is difficult or impossible to randomly assign participants to separate conditions, resulting in a change in DV that may be due to participant variables, reducing internal validity.

Question 11

Natural Experiments:

Answer 11

The two levels of independent variables have (or will) occurred naturally (in the real world) without the influence of the researcher. The researcher simply records the change in the dependent variable between the two levels of IV.

Question 12

Where can a Natural experiment happen?

Answer 12

Natural experiments can happen whenever an event causes people to form into levels of the independent variable. For example, this could be a literal natural event like a disaster or political decisions that only impact some members of a community.

Question 13

Variables in Natural experiments

Answer 13

The independent variable (IV) is NOT changed by the researcher between the conditions of the experiment. Changes in the dependant variable (DV) are still measured but other possible variables that could change the DV cannot be controlled.

Question 14

Natural experiments
Evaluation
✅

Answer 14

• Natural experiments allow research in areas that could not happen in controlled experimentation, either due to ethical or cost reasons.

• High in external validity as natural experiments are an example of real behaviour occurring in the real world free of demand characteristics.

Question 15

Natural experiments
Evaluation
❌

Answer 15

• As these events have already or will happen regardless of the researcher, they have no influence. This means extraneous variables can’t be controlled, so th researcher shouldn’t claim they have found a cause and effect relationship.

• These are often very rare events that can’t be replicated exactly to test for rellability.

Question 16

Quasi- experiments

Answer 16

Participants cannot be randomly assigned between levels of IV.
Often because the level of IV is an innate characteristic of the participants.

Question 17

What characteristics do psychologist want to study in quasi-experiments ?

Answer 17

There is a wide range of characteristics that psychologists would like to study, but these characteristics already exist in the sample, for example, gender, age, income level, educational level, and people with our without a mental health condition.

Question 18

Variables in quasi-experiments

Answer 18

Independent variable (IV) already exists in the participants so participants cant be randomised between the conditions of the experiment. The difference in the dependant variable (DV) will be measured while all other possible variables that could change the DV are kept constant.

Question 19

Quasi-experiments
Evaluation
✅

Answer 19

• Quasi-experiments are the only way to experimentally study factors that are pre-existing characteristics of participants.

Question 20

Quasi-experiments
Evaluation
❌

Answer 20

• There may be other factors related to the level of IV that cannot be contro for, these change systematically between the levels of IV and alter the measurement of the dependant variable. These are known as confounding variables.