Field and Laboratory Experiments

Question 1

Fill in the blank.

Experiments look for the _______ that manipulated variables (__________) have on measured variables (___________).

Answer 1

effect
independent variables
dependent variables

Question 2

What is a laboratory experiment?
What study has one?

Answer 2

-Takes place in an artificial highly controlled environment.
-The experimenter manipulates the IV to measure the impact on the DV.
-Pats attention to eliminating effects of other extraneous variables by controlling them (removing or keeping constant).
-Baddleys memory experiment.

Question 3

What is a field experiment?
What study has one?

Answer 3

-Takes place in the participants natural environment.
-The experimenter manipulates the IV to measure the impact on the DV.
-Some variables cannot be controlled due to the unpredictability of these real life settings such as the public interacting with pps.
-An IV will still be altered for a DV to be measured against.
-Sebastian and Hernandez-Gil’s digit down experiment AND Sheriff’s Robber’s Cave experiment.

Question 4

Evaluate the description of a laboratory experiment.

Answer 4

An experiment in which the researcher manipulates the IV to measure its impact on the DV. It takes place in an artificial and controlled environment.

Question 5

Evaluate the ecological validity of a laboratory experiment.

Answer 5

As the experiment takes place in an artificial environment, and often used artificial tasks, the behaviour of participants may not reflect their behaviour in everyday life.

Question 6

Evaluate the internal validity of a laboratory experiment.

Answer 6

As the experiment has full control over the environment, they can usually control all extraneous variables to prevent confounding variables impacting the DV, this means the experimenters can be confident that any changes seen in the DV are due to the manipulation of the IV alone. They can keep all other variables controlled, or at least consistent between conditions.

Question 7

Evaluate the internal validity of a laboratory experiment.

Answer 7

As the experiment has full control over the environment, they can usually control all extraneous variables to prevent confounding variables impacting the DV, this means the experimenters can be confident that any changes seen in the DV are due to the manipulation of the IV alone. They can keep all other variables controlled, or at least consistent between conditions.

Question 8

Evaluate the reliability of a laboratory experiment.

Answer 8

As the experimenter has full control over the environment, they can usually create a standardised experience for all participants; control over situational variables and control over all apparatus used. This means the experiment can easily be replicated to check for consistency of results over time.

Question 9

Evaluate the demand characteristics of a laboratory experiment.

Answer 9

As the experiment takes place in an artificial environment, the participant is usually fully aware that they are taking part in an experiment. This means they may guess the aim of the experiment (due to behaviour of the experimenter) and alter their behaviours to meet the demands of the experiment, impacting internal validity.

Question 10

Evaluate the description of a field experiment.

Answer 10

An experiment in which the researcher manipulated the IV to measure its impact on the DV. It takes place in the participants’ natural environment.

Question 11

Evaluate the ecological validity of a field experiment.

Answer 11

As the experiment takes place in the pps natural environment, the behaviours shown in the experiment will be true reflections of everyday behaviour.

Question 12

Evaluate the internal validity of a field experiment.

Answer 12

As the experiment is in a natural setting, the experimenter does not have full control over the environment, they cannot usually control all extraneous variables to prevent confounding variables impacting the DV, this means the experimenters might not be confident that any changes seen in the DV are due to the manipulation of the IV alone. They may struggle to keep situational variables controlled.

Question 13

Evaluate the reliability of a field experiment.

Answer 13

As the experimenter does not have full control over the environment, they cannot always create a standardised experience for all participants; control over situational variables may be limited. This means the experiment’s procedure might not easily be replicated exactly to check for consistency of results over time.

Question 14

Evaluate the demand characteristics of a field experiment.

Answer 14

As the experiment takes place in a natural environment, it is possible that sometimes, the participants will not know that they are participants in an experiment. This means they will not show demand characteristics, leading to high validity of their behaviour.

Question 15

What are 4 strengths of laboratory experiments?

Answer 15

1) High control over extraneous variables means they cannot confound the results so a “cause and affect” relationship can be established.
2) Reliable results as the conditions created can be replicated.
3) High internal validity as variables can be measured accurately with the tools made available in a lab setting.
4) No ethical issues as it’s easy to get informed consent, participants can withdraw be there’s no need to deceive.

Question 16

What are the 3 weaknesses of a laboratory experiment?

Answer 16

1) Lack ecological validity in the data collected as the artificial nature of laboratory experiments can cast doubt over whether the results reflect the nature of real-life scenarios.
2) High risk of demand characteristics as participants may alter their behaviour based on the interpretation of the aim of the experiment.
3) Risk of experimenter bias as their expectations by alter the interpretation of results.

Question 17

What are the 3 strengths of field experiments?

Answer 17

1) Higher ecological validity as the natural setting will relate to real life.
2) Demand characteristics are less of an issue as participants are less likely to adjust their natural behaviour as they might not know they are in a study.
3) Less risk of experimenter effects as participants don’t know the researcher so they aren’t affected by how they interact with them.

Question 18

What are the 4 weaknesses of field experiments?

Answer 18

1) Extraneous variables can confound results due to the reduced control experimenters have which makes it difficult to find truly casual effects between independent and dependent variables.
2) Lacks reliability as precise replication if the natural environment is difficult as you cant retest the exact conditions.
3) Susceptible to sample bias, as participants are often not randomly allocated to experimental conditions.
4) Ethical issues as there’s no informed consent.

Question 19

What are 4 things you need to consider when asked to design an experiment?

Answer 19

-Is it a lab or a field experiment?

-What are the IV and DV – how will you test the different conditions? How will you measure the different conditions?

-What experimental design will you use?

-What variables will you control?