The Experimental Method: Experiments Flashcards
What is the “experimental method”, or a “laboratory experiment”?
An experiment in which all of the variables are as controlled as possible. Artificial environments can be created.
What are the advantages of a laboratory experiment?
- All of the variables within the experiment are controlled, which increases RELIABILITY.
- The experiment can also easily be recreated - it is REPLICABLE.
- You can force the pace of research.
- Since the IV is all that changes and there are high levels of control, it is easy to establish a CAUSAL RELATIONSHIP.
- Participants will be aware that they are in an experiment, which makes the method ETHICALLY acceptable.
What are the disadvantages of a laboratory experiment?
- It is in a controlled, artificial environment that cannot be generalized to real life. It lacks ECOLOGICAL VALIDITY.
- Participants may change behaviour due to demand characteristics and become confounding variables.
- Extraneous variables are sometimes incredibly hard or expensive to control, e.g. natural ability to remember things.
- Artificial controlled environments are expensive to create.
What is a field experiment?
An experiment using the scientific method to examine an interaction in the real world (and not in the laboratory). The independent variable is controlled, but everything else is left.
How are experiments usually carried out in terms of groups?
Participants are randomized into a control group and treatment groups. After the experiment, the outcomes of these groups are compared.
What are the advantages of a field experiment?
- It happens in a natural environment, so it has a HIGH ECOLOGICAL VALIDITY.
- Allows us to study things that would be difficult to study in a laboratory.
What are the disadvantages of a field experiment?
- You cannot control the variables, so it lacks RELIABILITY.
- A confounding/extraneous variable could contaminate the results and provide unreliable data.
- Harder to measure results as it happens naturally and you cannot interfere with the experiment
- Participants may be unaware of being studied, creating ETHICAL ISSUES.
What is a natural experiment?
An experiment investigating the relationship between the IV and the DV where the IV varies NATURALLY. You take a real life situation that would happen regardless of your study, and you measure it.
What are the advantages of a natural experiment?
- It allows research where the independent variable can’t be manipulated for ethical or practical reasons.
- It enables psychologists to study “real” problems, e.g. the effects of disaster on health. It has HIGH VALIDITY.
What are the disadvantages of a natural experiment?
- You can’t demonstrate a CAUSAL RELATIONSHIP because the IV isn’t directly manipulated.
- There is no control over extraneous variables, which may affect behaviour in many different ways. This is a threat to INTERNAL VALIDITY.
- It can only be used where conditions vary naturally.
- Participants may be unaware of being studied, creating ETHICAL ISSUES.
What is a quasi-experiment?
Investigates relationships between an IV and a DV where the IV is a characteristic of a person, e.g. gender.
What are the advantages of a quasi-experiment?
- It allows comparisons between types of people.
- It studies “real effects” - HIGH REALISM AND ECOLOGICAL VALIDITY.
What are the disadvantages of a quasi-experiment?
- Conditions must vary naturally.
- Participants may be aware of being studied, decreasing INTERNAL VALIDITY.
- The dependant variable may be measured via an artificial task, lowering ECOLOGICAL VALIDITY.
Give an example of a field experiment.
E.g. Observing nurses’ obedience to authority in the workplace when they are unaware of the experiment.
Give an example of a quasi-experiment.
E.g. Investigating gender differences using emotion - guessing programmes or spatial/ shape based worksheets.
