Experiments Flashcards
Lab experiments
- controlled enviroment where extraneous & confounding variables can be regulated
- participants go to researcher
- IV is manipulated & effect on DV is recorded
Lab experiments strengths
- EV and CV can be controlled, effects can be minimised, cause & effects can be demonstrated (high internal validity)
- easily replicated, greater control means les chance of new IV introduced, findings can be confirmed = validity
Lab experiments limitations
- may lack generalisability, lab may be artificial and ptsp aware they’re studied, behaviour not natural, not generalised to everyday life(low external validity
- demand characteristics, there are cues that invite particular response from ptsp, findings explained by cues rather than effect of IV (low external validity)
Field experiments
-natural setting
- researcher goes to participant
- IV is manipulated and DV is recorded
Field experiments strengths
-natural enviroment, comfortable and authentic, results more generalised to everyday life
-ptsp unaware of being studies, behave normally findings generalised,, greater external validity
Field experiments limitations
- difficult to control IV & DV, changes in DV may be due to EV and CV not IV, more difficult to establish cause & effect
- ethical issues, not given consent, invasion of privacy
Natural experiments
-IV changes due to natural circumstances
-experiment does not manipulate IV, someone or something else causes IV to vary (not IV) - IV would vary even if experimenter didn’t intend to
- DV may be naturally occurring
Natural experiments strengths
-may be the only practical/ethical option, may be unethical to manipulate IV, only way casual researcher can be done
- greater external validity, involve real world issues( natural disasters and stress), findings relevant to real experiences
Natural experiments limitations
-Natural event rare, many ‘one-offs’ reduce oppotunities, limit scope for generalised findings to other situations
-ptsp not randomly allocated, no control over which ptsp in which conditions as IV is pre-existing, result in CV that aren’t controlled
Quasi experiment
- participants not randomised
- IV based on pre-existing differences (age,gender), not manipulated
- DV may be naturally occurring
Quasi experiments strengths
- High control, carried out under controlled conditions share strengths of lab, replication is possible
- comparisons can be made between people, IV is a difference between people, therefore comparisons can be made
Quasi experiments limitations
-Ptsp not randomly allocated, no control which conditions with who as IV is pre-existing, ptsp variables may have caused change in DV acting as CV
- casual relationships not demonstrated, doesn’t nit manipulate/control IV, not certain if changed in DV was due to IV
