Define Internal and External Validity and Explain Five Threats to Internal

question 29

Essay

Define internal and external validity and explain five threats to internal validity and two threats to external validity.

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Definitions:

Ocean Basins

The underwater depressions of the Earth's surface that contain the bulk of the planet's ocean water.

Abyssal Plains

Vast, flat areas of the deep ocean floor, situated at depths between 3,000 and 6,000 meters below sea level.

Seamounts

Underwater mountains formed by volcanic activity, which rise from the ocean floor but do not reach the surface.

Island Chains

Groups of islands formed close to one another, often as a result of volcanic activity along oceanic ridges or subduction zones.