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A Factor in Determining the Usefulness of an Examination as a Measure

question 24

Multiple Choice

A factor in determining the usefulness of an examination as a measure of demonstrated ability is the amount of spread that occurs in the grades. If the spread or variation of examination scores is very small, it usually means that the examination was either too hard or too easy. However, if the variance of scores is moderately large, then there is a definite difference in scores between "better," "average," and "poorer" students. A group of attorneys in a Midwest state has been given the task of making up this year's bar examination for the state. The examination has 400 total possible points, and from the history of past examinations, it is known that a standard deviation of around 56 points is desirable. Of course, too large or too small a standard deviation is not good. The attorneys want to test their examination to see how good it is. A preliminary version of the examination (with slight modification to protect the integrity of the real examination) is given to a random sample of 24 newly graduated law students. Their scores give a sample standard deviation of 77 points. Find a 99% confidence interval for the population variance.

Definitions:

Meta-analysis

is a statistical technique that combines the results of multiple scientific studies to arrive at a comprehensive conclusion.

Interaction

Interaction refers to the reciprocal action or influence between two or more entities, objects, or individuals.

Independent Variable

The variable in an experiment that is manipulated to observe its effect on the dependent variable.

Dependent Variable

The variable in experimental research that is measured to assess any changes in response to the manipulation of the independent variable.