Research Methods- Types of experiment Flashcards
Laboratory (lab) experiment -
An experiment that takes place in a controlled environment within which the researcher manipulates the IV and records the effect on the DV, whilst maintaining strict control of extraneous variables.
Field experiment -
An experiment that takes place in a natural setting within which the researcher manipulates the IV and records the effect on the DV.
Natural experiment -
An experiment where the change in the IV is not brought about by the researcher but would have happened even if the researcher had not been there. The researcher records the effect on the DV.
Quasi-experiment -
A study that is almost an experiment but lacks key ingredients. The IV has not been determined by anyone (the researcher or any other person) - the ‘variables’ simply exist, such as being old or young. Strictly speaking this is not an experiment.
What is a laboratory experiment?
A laboratory experiment is conducted in a highly controlled environment, not necessarily a lab, where conditions can be well regulated.
What is the main strength of laboratory experiments?
They have high control over extraneous variables, allowing researchers to confidently establish cause and effect (high internal validity).
Why is replication easier in laboratory experiments?
The high level of control ensures that new extraneous variables are not introduced, making it easier to repeat the experiment and verify results.
What are demand characteristics, and how do they affect laboratory experiments?
Demand characteristics occur when participants behave unnaturally because they are aware they are being tested, potentially skewing results.
What is a limitation of laboratory experiments in terms of generalisability?
The lab environment may be artificial, leading to unnatural participant behavior that cannot be generalized to everyday life (low external validity).
What is mundane realism, and why is it a limitation in laboratory experiments?
Mundane realism refers to how well a task reflects real-life experiences. Lab tasks (e.g., recalling word lists) often lack mundane realism, reducing the validity of findings.
What is a field experiment?
A field experiment involves manipulating the independent variable (IV) in a natural, everyday setting outside the lab.
What is the main strength of field experiments?
They have higher mundane realism and external validity because the environment is more natural, and participants may be unaware they are being studied.
What is a limitation of field experiments?
There is less control over extraneous variables, making it harder to establish cause and effect and replicate the study precisely.
What ethical issue is associated with field experiments?
Participants may be unaware they are being studied, raising concerns about consent and invasion of privacy.
What is a natural experiment?
A natural experiment occurs when the researcher takes advantage of a pre-existing independent variable (IV) that would have changed even without the researcher’s involvement.
Why do natural experiments often have high external validity?
They study real-life issues and problems as they happen, making the findings more applicable to everyday situations.
What is a strength of natural experiments?
They allow research on topics that may not be feasible for practical or ethical reasons, such as studying the effects of natural disasters or institutionalization.
What is a limitation of natural experiments?
Naturally occurring events may be rare, limiting research opportunities and the generalizability of findings.
What is a quasi-experiment?
A quasi-experiment involves an IV based on an existing difference between people (e.g., age, gender) that is not manipulated by the researcher.
What is a strength of quasi-experiments?
They are often conducted under controlled conditions, sharing the strengths of laboratory experiments.
What is a limitation of quasi-experiments?
Participants cannot be randomly allocated to conditions, which may introduce confounding variables.
How do natural and quasi-experiments differ from laboratory experiments?
Natural and quasi-experiments involve IVs that are not manipulated by the researcher, whereas laboratory experiments involve deliberate manipulation of the IV in a controlled setting.
What is an example of a natural experiment?
Studying the effects of early vs. late adoption on Romanian orphans, where the IV (adoption timing) was not manipulated by the researcher.
What is an example of a quasi-experiment?
Comparing anxiety levels between phobic and non-phobic patients, where the IV (having a phobia) is an existing difference, not manipulated by the researcher.
