Definitions
1. Operational Definition: The definition of a variable in terms of operations needed to produce or measure that variable.
2. Measurement Reliability: A measurement is reliable when it is consistent across experimenters and/or time.
3. Measurement Validity: A measurement is valid when it is measuring what it claims to be measuring (truthful).
4. Dependent Variable (sometimes called criterion variable): The target variable. The variable that is assessed as being the result of or predicted by other variables.
5. Independent Variable (sometimes called predictor variable): The manipulated variable. Variation in the IV is predicted to be associated with variation in DV.
6. Hypothesis: Operationally defined hypothetical statement that specifies a predicted relation (causal, correlational) between the IV and DV.
7. Extraneous Variable(s): The variable(s), associated with the IV, that influences the DV.
8. Internal Validity of a Study: The extent to which the design adequately tests the hypothesis. Poor tests of hypotheses may result from poor operationalization of the variables, lack of validity or reliability of the measures, or the presence of extraneous variables.
9. External Validity of a Study: The extent to which you can feel sure that the
results obtain can generalize to other subjects...
A) who are in other settings
B) who are measured using other instruments,
C) who are studied by other experiments using other measures
D) who are living at other times.
E) who ...etc.