What Is the Value of the Item-Discrimination Index for an Item

question 16

Multiple Choice

What is the value of the item-discrimination index for an item that all the students in the higher-scoring group answered correctly but that no one in the lower-scoring group answered correctly?

• A) -1
• B) +1
• C) .50
• D) .25

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Definitions:

Error Variance

The portion of variation in a set of observations that arises from random factors as opposed to systematic influences.

Imperfect Matching

A scenario in research where participants in different groups or conditions are not perfectly comparable due to varying characteristics that may affect the outcome.

Crossover Design

A research method where participants receive more than one treatment in a specific order, allowing comparison of different interventions within the same group.

Dependent Variable

The outcome variable being measured in an experiment or study, which is hypothesized to depend on or be affected by the independent variable(s).