Experimental design Flashcards
The scientific method
is a systematic approach for planning, conducting and reporting research which involves collecting empirical evidence
Empirical evidence
data collected directly from observation or experiment
Experiment
a controlled research study testing the effect of changing one variable on another. An example of quantitative research that generates numerical data
Types of experiments
True experiment
Field experiment
Quasi experiment
Natural experiment
True experiment
when the IV is manipulated and DV is measured under controlled conditions. Participants are randomly allocated to conditions
Field experiment
an experiment done in a natural setting. There is less control over variables
quasi experiment
no IV is manipulated and participants cannot be randomly allocated to conditions. Instead their traits allocate them to groups e.g. age, gender
Natural experiment
an experiment that is a result of a naturally occurring event e.g. changes in behavior after a change in law or changes in behavior after the introduction of television to isolated communities
Extraneous variables
variables other than the independent variable that have the potential to cause unwanted effects on the dependent variable
confounding variable
variables other than the IV that directly and systematically had an effect on the DV (often related to the design of the experiment)
Experimental designs
Repeated measures
matched pair
Independent measures
repeated measures
- Each participant completes both conditions (the control and experimental)
Participant differences are eliminated (e.g. the same IQ etc.
Matched pair
- Participants with similar qualities that may effect the study are matched up together, you then randomly split them into the two groups so that both groups have similar characteristics
E.g. if you are looking at music’s effect on school grades you might match people with similar historic academic performances and similar subjects
Independent measures
- Participants are randomly (have an equal chance of being assigned to wither group) allocated to the control and groups
- Participants complete only one of the conditions
What are the ethical considerations
- deception
- protection from undue stress or harm
- debriefing
- informed consent
- anonymity
- right to withdrawl
ethical consideration
what is deception
- Knowing things about the experiment may change how people perform in the study
- You can use deception if its justified, it doesn’t cause harm or distress and the participant is debriefed after the experiment so that they understand what actually happened and the true purpose of the study
ethical consideration
protection from undue stress or harm
- Throughout the experiment participants are protected form all forms of physical and mental harm
- There are no negative consequences suffered from the study
- Care must be taken with vulnerable groups