Describe the Relationship Between Reliability and Validity

question 18

Essay

Describe the relationship between reliability and validity. (Note: Your description should answer the following two questions: Is it possible to have a reliable but invalid measure? Is it possible to have an unreliable but valid measure?)

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Definitions:

Standard Deviation

A measure of the amount of variation or dispersion in a set of values.

Confidence Interval

An estimated range of values which is likely to include an unknown population parameter, calculated from a given set of sample data.

Margin of Error

An expression of the amount of random sampling error in a survey's results, indicating a range within which the true value lies at a certain confidence level.

Probability

The extent to which an event is likely to occur, measured by the ratio of the favorable cases to the whole number of cases possible.