Types of Experiments Flashcards
What is Validity?
It is the extent to which an observed effect is genuine. This
can be split into internal (within the investigation) an external
(outside of the investigation setting) validity.
What is Reliability?
It refers to how consistent the findings from an investigation or measuring device are. A measuring device is said to be reliable if it produces consistent results every time it is used.
What is Mundane realism?
Mundane realism describes the degree to which the materials and procedures involved in an experiment are similar to events that occur in the real world.
What is Generalisability?
It is the extent to which results or findings obtained
from a sample are applicable to a broader population.
What are the qualities of lab experiments
They are heavily controlled experiments in which the IV is manipulated by the investigator, participants are aware they are in the experiment.
What are the strengths of lab experiments
Lab experiments have high control over extraneous variables, this means that the researcher can be sure that the effect on the DV is likely to be a result of the manipulation of the IV.
Replication is more possible because of the high level of control, replication is vital to check the results of any study to see whether the finding is valid (accurate), not just a one off.
What are the drawbacks of lab experiments
Lab experiments may lack generalisability because the environment may be artificial and not like everyday life (participants may behave in unusual ways so their behaviour cannot always be generalised beyond the research setting – low external validity).
Demand characteristics may arise because they are aware that they are being tested.
Lacks mundane realism, the tasks given do not reflect real-life experiences.
What are the qualities of field experiments
Field experiments are carried out in natural conditions, in which the researcher manipulates the IV to measure the effect on the DV. The ‘field’ is considered to be any location that is not a laboratory. Participants in a field experiment typically do not know that they are taking part in an investigation.
What are the strengths of field experiments
Field experiments have higher mundane realism than lab experiments because the environment is more natural.
Thus field experiments may produce behaviour that is more valid and authentic because they are usually unaware that they are taking part.
What are the drawbacks of field experiments
There is a loss of control over extraneous variables. This mans cause and effect between the IV and DV is difficult to establish and precise replication is often not possible.
If participants are unaware they are being studies they cannot consent to being studied and the research might constitute an invasion of privacy (ethical issues).
What are the qualities of Natural experiments
In a natural experiment, the researcher does not manipulate the IV and instead examines the effect of an existing IV on the DV.
This IV is naturally occurring (such as a flood or earthquake) and the
behaviour of people affected is either compared to their own behaviour beforehand of with a control group that have not encountered the IV.
What are the strengths of Natural experiments
Natural experiments provide opportunities for research that may not otherwise be undertaken for practical reasons.
Natural experiments often have high external validity because they involve the study of real-life issues and problems as they happen, such as the effects of a natural disaster on stress levels.
What are the qualities of Quasi Experiments
Quasi experiments also contain a naturally occurring IV, but one that already exists, such as a difference between people (gender, age, personality trait etc).
The researcher examines the effect of this IV on the DV, quasi experiments do not have to be conducted in a natural setting, although they often are. They may also be conducted in a lab setting, under controlled conditions.
What are the drawbacks of Natural experiments
A naturally occurring event may only happen rarely, reducing the opportunity for research.
Another issue is that participants may not be randomly allocated to experimental conditions (this only applies when there is an independent groups design). This means the researcher cannot be sure whether the IV affected the DV.
What are the strengths of Quasi experiments?
Quasi experiments are often carried out
under lab conditions and therefore share
the strengths of a lab experiment:
Replication
Control over confounding variables.
