In a Study on the Effects of Caffeine on Reaction

question 33

Multiple Choice

In a study on the effects of caffeine on reaction time, one group of participants ingests two cups of coffee before being tested. A second group takes four cups, and a third group takes eight cups. Before the study, participants are asked about the average number of cups they drink per day and that information is used when assigning participants to groups. What is the design?

• A)multilevel, matched groups
• B)independent groups, single factor
• C)repeated measures, multilevel
• D)multilevel, nonequivalent groups

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Definitions:

Operating Characteristic

A function or curve that describes the discriminating ability of a test across various conditions or thresholds.

Sample Size

The number of individuals, observations, or data points collected or selected from a population for the purpose of analysis.

Type II Error

Occurs when a statistical test fails to reject a false null hypothesis, meaning it wrongly indicates there is no effect when one exists.

Standard Deviation

A measure of the dispersion or spread of a set of values, indicating how much the values in a data set vary from the mean.