Research methodology (research design and data collection): Why is the before and after design is the best design?

Question

Why is the before and after design is the best design?

Shay 1vcc · Accepted Answer

This design is superior to the above two designs as it avoids extraneous variation resulting both from the passage of time and from non-comparability of the test and control areas

Research methodology (research design and data collection)

Why is the before and after design is the best design?

This design is superior to the above two designs as it avoids extraneous variation resulting both from the passage of time and from non-comparability of the test and control areas

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