types of experiment Flashcards
name the different types of experiments
- laboratory
- field
- natural
- quasi
define laboratory experiment
- highly controlled environment
- not always lab
strengths of laboratory experiments
+)
P: high control over confounding & extraneous variables
E: researcher can ensure any effect on DV is due to result of manipulation of IV
T: we can be more certain about demonstrating cause and effect, giving the experiment high internal validity
+)
P: replication easier than other types of experiments
E: due to high level of control which ensures new extraneous variables not introduced when repeating experiment
limitations of laboratory experiments
-)
P: may lack generalisability
E: lab environment may be artificial & not represent everyday life. also, in unfamiliar context participants may behave in unusual way so behaviour can’t be generalised beyond research setting.
T: low external validity
-)
P: participants usually aware they’re being tested in lab experiment
E: may give rise to ‘unnatural’ behaviour (demand characteristics)
-)
P: tasks don’t represent everyday life
E: eg. recalling unconnected list of words in memory experiment
T: low mundane realism
describe field experiments
- IV manipulate in natural, more everyday setting
- researcher goes to participants usual environment
strength of field experiments
+)
P: higher mundane realism than lab
E: environment more natural as participants may be unaware they’re being studied
T: produce behaviour that’s more valid & authentic (high external validity)
limitations of field experiments
-)
P: loss of control of CVs & EVs
E: cause and effect between IV & DV may be much more difficult to establish & precise replication is often not possible
-)
P: ethical issues
E: participants may be unaware they’re being studied so can’t consent & research may be invasion of privacy
describe natural experiments
- like lab/field as researcher measures effect of IV on DV
- researcher has no control over IV
- may be tested in lab
- DV may also be naturally occurring or devised by experimenter
strengths of natural experiments
+)
P: opportunities for research that may not be undertaken for practical/ethical reasons
E: eg. studies of institutionalised romanian orphans
+)
P: high external validity
E: involve study of real-world issues & problems as they happen eg. effect of natural disaster on stress levels
limitations of natural experiments
-)
P: naturally occurring event may only happen rarely
E: reduces opportunities for research & limits scope for generalising findings to other similar situations
-)
P: participants may not be randomly allocated to experimental conditions (independent groups design)
E: researcher might be less certain of whether the IV affected the DV
-)
P: research may be conducted in lab
E: lacks realism & demand characteristics may occur
describe quasi experiments
- IV based on existing difference between people (eg. age, gender)
- Iv hasn’t been manipulated & just exists
- DV may be naturally occurring or devised by experimenter
strengths of quasi experiment
+)
P: carried out under controlled conditions
E: replicability, high internal validity
limitations of quasi experiment
-)
P: can’t randomly allocate participants to conditions
E: may be confounding variables
-)
P: IV isn’t deliberately changed by researcher
E: cannot be sure if IV has caused any observed change
