Independent variable
The variable that the experimenter changes is interested in its effect. We want to see the effect of the IV on the DV
Dependent Variable
the thing we measure, it measures the effect of the IV
Extraneous Variable
anything that affects the DV that isn’t the IV
confounding variable
If an extraneous variable does actually affect the experiment it is called a confounding variable
Laboratory experiment
takes place in an artificial environment with a high degree of control
Field experiment
takes place in a natural environment, but the experimenter is still manipulating the IV
Natural experiment
takes place in a natural environment and the experimenter is NOT manipulating the IV, but rather observing and using information produced by natural circumstances
Control Condition
The IV is NOT present. This is the base level to compare the experimental condition with
Experimental Condition
the IV IS present. You are testing the effect of the IV on the DV
Experimental Group
Participants are exposed to the experimental condition
Control Group
Participants who are exposed to the control condition
(independent groups design)
All participants who have been selected for an experiment are just as likely to be in one group as the other
Demand Characteristics:
parts of the experiment may give away the aims and therefore cause participants to change their behaviour to do what they think they should (this can be conscious or unconscious)
Participant Variables
Individual differences between participants (can create differences in behaviour in a study and alter the outcome instead of differences being solely due to the IV)
Order Effects
Practice & fatigue effects are the consequences of participating in a study more than once (repeated measures design) and can cause changes in performance between conditions not due to the IV
Practice Effect
Performance improves because the participant has experienced the experimental task more than once (due to learning or familiarity)
Fatigue Effect
Performance declines because the participant has done the task more than once (due to boredom or tiredness)
Counterbalancing
used to overcome order effects in a repeated measures design experiment. Each possible order of levels of the IV is done by different subgroups. Can be ABBA, BAAB, ABAB, BABA, etc.
Standardization
Reliability
The extent to which a procedure, task, or measure is consistent (eg. Do you get the same results each time you do it)
Validity
The extent to which the researcher is testing what they claim to be testing
Internal Validity
The extent to which a piece of evidence supports a claim about cause and effect, within the context of a particular study
External Validity
The validity of applying the conclusions of a scientific study outside the context of that study
Ecological Validity
The extent to which the findings in one situation would generalise to other situations. This is influenced by whether the situation represents the real world effectively and whether the task is relevant to real life