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Program Evaluation Glossary
"V"
- Validity
- The extent to which a measurement instrument or test accurately
measures what it is supposed to measure.
- Validity Assessment
- The procedures necessary to demonstrate that a question or
questions are measuring the concepts that they were designed
to measure.
- Variable
- Variables can be classified into three categories:
- Independent (input, manipulated,
treatment, or stimulus) variables, so called because
they are "independent" of the outcome;
instead, they are presumed to cause, effect, or influence
the outcome.
- Dependent (output, outcome,
response) variables, so called because they are "dependent"
on the independent variable; the outcome presumably
depends on how these input variables are managed or
manipulated.
- Control (background, classificatory,
or organismic) variables, so called because they need
to be controlled, held constant, or randomized so
that their effects are neutralized, canceled out,
or equated for all conditions.
- Variance
- A measure of the spread of the values in a distribution.
The larger the variance, the larger the distance of the individual
cases from the group mean.
- Verification
- An effort to test the accuracy of the questionnaire response
data. The concern is uniquely with data accuracy and deals
with neither the reliability nor the validity of measures.
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