Chapter 6 Research Methods - Experiments Flashcards
Experiments - Experimental method - Aims?
Purpose of the investigation.
Experiments - Experimental method - Hypotheses?
Testable, operationalised statement.
Experiments - Experimental method - Directional or non-directional?
Identifying a difference/correlation or not. Choice depends on previous theory/research.
Experiments - Variables - IVs & DVs?
IV manipulated, DV measured.
Experiments - Variables - Levels of the IV?
Experimental & control conditions.
Experiments - Variables - Operationalisation?
Defining variables so they can be measured.
Experiments - Research issues - Extraneous variables?
Nuisance variables but randomly distributed.
Experiments - Research issues - Confounding variables?
Vary systematically with IV.
Experiments - Research issues - Demand characteristics?
Pts second guess the aims, alter their behaviour.
Experiments - Research issues - Investigator effects?
Influence of researcher on DV/design decisions.
Experiments - Research issues - Randomisation?
Chance methods to reduce researcher’s bias.
Experiments - Research issues - Standardisation?
Ensuring all pts have the same experience.
Experiments - Experimental designs - Independent groups?
Pts in each condition of experiment are different.
Experiments - Experimental designs - Repeated measures?
All pts take part in all conditions.
Experiments - Experimental designs - Matched pairs?
Similar pts paired on participant variables, allocated to condition A or B
Experiments - Evaluation of experimental designs - Independent groups?
- Participant variables not controlled (use random allocation).
- Less economical. No order effects,
Experiments - Evaluation of experimental designs - Repeated measures?
Order effects (use counterbalancing). Demand characteristics. Participant variables controlled. More economical.
Experiments - Evaluation of experimental designs - Matched pairs?
No order effects. Cannot match pts exactly. Time-consuming.
Types of experiment - Lab experiments?
IV is manipulated in a controlled setting. Pts go to researcher.
Types of experiment - Field experiments?
IV is manipluated in natural setting. Researcher goes to pts.
Types of experiment - Natural experiments?
IV changes naturally. DV/setting may be natural or in a lab.
Types of experiment - Quasi-experiments?
IV based on an existing difference between people, effect on DV is recorded.
Evaluations of the types of experiments - Lab experiments?
S - High internal validity (control confounding & extraneous variables, cause & effect shown), replication more possible (support for findings).
L - Low external validity (lack of generalisability, low mundane realism), low internal validity (demand characteristics).
Evaluations of the types of experiments - Field experiments?
S - Higher external validity (more authentic, realism).
L - Lower internal validity (less control). Ethical issues (consent not possible).
Evaluations of the types of experiments - Natural experiments?
S - Only option for practical/ethical reasons, high external validity (real-world problems).
L - Limited opportunities, no random allocation (confounding variables), no manipulation of IV (can’t claim cause & effect).
Evaluations of the types of experiments - Quasi-experiments?
S - Carried out under controlled conditions like a lab experiment.
L - No random allocation, no manipulation of IV (can’t claim cause & effect).
