L1 - Experimental Methods Flashcards
what is the INDEPENDENT VARIABLE?
This is the variable that the RESEARCHER MANIPULATES in order to DETERMINE ITS EFFECT ON THE DEPENDENT VARIABLE
The IV may be DIVIDED INTO LEVELS, sometimes referred to as EXPERIMENTAL CONDITIONS.
To provide a STANDARD AGAINST WHICH EXPERIMENTAL CONDITIONS CAN BE COMPARED there may be a CONTROL CONDITION where the IV is NOT MANIPULATED AT ALL
what is the DEPENDENT VARIABLE?
this is the variable that is BEING MEASURED
the IV and the DV should be OPERATIONALISED.
OPERATIONALISATION is DEFINING THE VARIABLES in such a way as to MAKE THEM MEASURABLE
what are EXTRANEOUS VARIABLES (EV) ?
These are any variables (OTHER THAN THE IV) which COULD AFFECT THE DV
what are CONFOUNDING VARIABLES (CV) ?
These are any variables (OTHER THAN THE IV) that HAVE AFFECTED THE DV
what are LABORATORY EXPERIMENTS? - PT 1
LABORATORY EXPERIMENTS are carried out in a CONTROLLED ENVIRONMENT, allowing the researcher to EXERT A HIGH LEVEL OF CONTROL OVER THE IV and ELIMINATE ANY EVs
The researcher can then MEASURE THE CHANGE IN THE DV CAUSED BY THEIR MANIPULATION OF THE IV
what are LABORATORY EXPERIMENTS? - PT 2
PARTICIPANTS (people who take part in psychological research) are RANDOMLY ALLOCATED TO A CONDITION. This means neither the experimenter nor the pp decides which CONDITION the pp is placed in.
An UNPREDICTABLE METHOD (such as flipping a coin or drawing names out of a hat) is used to decide
what are the ADVANTAGES of LABORATORY EXPERIMENTS?
1) HIGH LEVEL OF CONTROL - easy to control for ANY EV, PREVENTING THEM FROM BECOMING CV
2) CAUSE AND EFFECT CAN BE ESTABLISHED because the researcher can manipulate the IV
3) a WELL CONTROLLED LAB EXPERIMENT can be EASILY REPLICATED by other researchers to see if SIMILAR RESULTS can be obtained - if the FINDINGS ARE SIMILAR to the ORIGINAL STUDY then the RESULTS ARE RELIABLE
what are the DISADVANTAGES of LABORATORY EXPERIMENTS?
1) STRONG CHANCE OF DEMAND CHARACTERISTICS with a LABORATORY EXPERIMENT, this is a TYPE OF EV where pps GUESS WHAT THE EXPERIMENT IS ABOUT and ALTER THEIR BEHAVIOUR
2) by establishing a HIGH LEVEL OF CONTROL OVER THE IV and EV the experimental situation can LACK MUNDANE REALISM (the extent to which an experiment reflects real life). This means the study DOES NOT HAVE ECOLOGICAL VALIDITY (the ability to generalise findings of research to the real world)
what are FIELD EXPERIMENTS?
FIELD EXPERIMENTS are CARRIED OUT IN THE REAL WORLD
The IV is MANIPULATED by the researcher to see the EFFECT ON THE DV
what are the ADVANTAGES OF FIELD EXPERIMENTS?
1) there is MORE MUNDANE REALISM and ECOLOGICAL VALIDITY THAN IN A LABORATORY
2) because the researcher CAN MANIPULATE THE IV a CAUSE AND EFFECT RELATIONSHIP BETWEEN THE IV and the DV CAN BE ESTABLISHED
3) there is LESS CHANCE of DEMAND CHARACTERISTICS because in a FIELD EXPERIMENT the pps might NOT EVEN BE AWARE that they are TAKING PART IN RESEARCH
what are the DISADVANTAGES of FIELD EXPERIMENTS?
1) MUCH LESS CONTROL OVER EV and so the EFFECT ON THE DV may NOT BE CAUSED BY MANIPULATION OF THE IV but by these EV. This means the research is NOT VALID (NOT MEASURING WHAT IT INTENDS TO MEASURE)
2) there is LESS CONTROL OVER THE SAMPLE (who is taking part in the experiment)
3) FIELD EXPERIMENTS may be FAR MORE DIFFICULT TO REPLICATE
what is a NATURAL EXPERIMENT?
in a NATURAL EXPERIMENT, the researcher TAKES ADVANTAGE of a NATURALLY OCCURRING IV to see its EFFECT ON THE DV
what are the ADVANTAGES of NATURAL EXPERIMENTS?
1) there is a HIGH LEVEL of MUNDANE REALISM and ECOLOGICAL VALIDITY
2) VERY USEFUL when it is IMPOSSIBLE or UNETHICAL to MANIPULATE THE IV/SAMPLE in a LABORATORY EXPERIMENT or FIELD EXPERIMENT
what are the DISADVANTAGES of NATURAL EXPERIMENTS?
1) LESS CONTROL OVER EV
2) DIFFICULT TO REPLICATE
3) FAR MORE DIFFICULT to DETERMINE CAUSE AND EFFECT
what are QUASI EXPERIMENTS?
QUASI EXPERIMENTS contain a NATURALLY OCCURRING IV.
However, in a QUASI EXPERIMENT, the naturally occurring IV is a DIFFERENCE BETWEEN PEOPLE THAT ALREADY EXISTS (such as gender or age)
the researcher examines the EFFECT OF THIS VARIABLE ON THE DV
