As the Proportion of People Who Get an Item on a Test

question 80

Multiple Choice

As the proportion of people who get an item on a test correct increases, the measure of item difficulty

• A)decreases.
• B)remains the same.
• C)increases.
• D)approaches chance.

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Definitions:

Central 68%

Refers to the property in a normal distribution where approximately 68% of the data points lie within one standard deviation of the mean.

Standard Deviation

The statistical measure that quantifies the dispersion or variability within a data set.

Mean

The arithmetic average of a set of numbers, calculated by adding them together and dividing by the count of the numbers.

Z-score

A numerical metric indicating how a specific value compares to the average of a dataset, expressed by the number of standard deviations away from that average.