research methods- types of experiment Flashcards
what is a laboratory experiment?
-controlled environment where EV and CVs can be regulated
-p’s go to researcher
-IV is manipulated and DV recorded
evaluate lab experiments
+EVs and CVs can be controlled
+can be more easily replicated
-may lack generalisability
-demand characteristics may be a problem
ao3 of lab experiments: EVs and CVs can be controlled
-means effect of EVs and CVs on the DV can be minimised
-cause and effect between the IV and DV can be demonstrated (high IV)
ao3 of lab experiments: can be more easily replicated
-greater control means less chance that new EVs introduced
-means findings can be confirmed, supporting their validity
ao3 of lab experiments: may lack generalisability
-controlled lab environment may be rather artificial and p’s aware they’re being studied
-behaviour may not be ‘natural’ and can’t be generalised to everyday life (low EV)
ao3 of lab experiments: demand characteristics may be a problem
-cues in the experimental situation that invite a particular response from p’s
-findings may be explained by these cues rather than the effect of the IV (lower IV)
what is a field experiment?
-natural setting
-researcher goes to p’s
-IV is manipulated and effect on the DV is recorded
evaluation of field experiments
+more natural environment
+p’s unaware of being studied
-more difficult to control CVs/EVs
-ethical issues
ao3 of field experiments: more natural environment
-p’s more comfortable and behaviour more authentic
-results may be more generalisable to everyday life
ao3 of field experiments: participants unaware of being studied
-more likely to behave as they normally do so the findings can be generalised
-study had greater external validity
ao3 of field experiments: more difficult to control CVs/EVs
-observed changes in the DV may not be due to the IV, but to CVs/EVs instead
-more difficult to establish cause and effect than in the lab
ao3 of field experiments: ethical issues
-p’s in a field experiment may not have given informed consent
-this is an invasion of p’s privacy, which raises ethical issues
what is a natural experiment?
-experimenter does not manipulate the IV- it does change, but someone or something else causes the IV to vary. IV would have varied even if the experimenter wasn’t interested
-DV may be naturally occurring (e.g. exam results) or may be devised by the experimenter and measured in the field or a lab
evaluation of natural experiments
+may be the only practical option
+greater external validity
-natural event may only occur rarely
-p’s are not randomly allocated
ao3 of natural experiments: may be the only practical/ethical option
-it may be unethical to manipulate IV, e.g. studying the effects of institutionalisation of children
-natural experiment may be the only way casual research can be done for such topics
ao3 of natural experiments: greater external validity
-natural experiments real-world issues, such as the effect of a natural disaster on stress levels
-this means the findings are revenant to real experiences
ao3 of natural experiments: natural event may only occur rarely
-many natural events are ‘one-offs’ and this reduces the opportunity for research
-may limit the scope for generalising findings to other similar situations
ao3 of natural experiments: p’s are not randomly allocated
-experimenter has no control over which p’s are placed in which condition as the IV is pre-existing
-may result in CVs that aren’t controlled, e.g. Romanian orphans adopted early may also be the friendlier
what is a quasi-experiment?
-IV is based on a pre-existing difference between people, e.g. age or gender
-no one has manipulated this variable, it simply exists
evaluate quasi-experiments
+ there’s often high control
+ comparisons can be made between people
- p’s are not randomly allocated
- causal relationships not demonstrated
ao3 of quasi-experiments: there’s often high control
-often carried out under controlled conditions and therefore shares some of the strengths of lab experiments
-this means, for example, replication is possible
ao3 of quasi-experiments: comparisons can be made between people
-in a quasi-experiment the IV is a difference between people, e.g. people with and without autism
-means that comparisons between different types of people can be made
ao3 of quasi-experiments: p’s are not randomly allocated
-experimenter has no control over which p’s are placed in which conditioning as the IV is pre-existing
-participant variables may have caused the change in the DV acting as a CV
ao3 of quasi-experiments: causal relationships not demonstrated
-as with a natural experimenter, the researcher does not manipulate/control the IV
-we cannot say for certain that any change in the DV was due to the IV
