Which of the Following Might Contain a Serious Threat to the External

question 11

Multiple Choice

Which of the following might contain a serious threat to the external validity of a study?

• A) a survey with a return rate of 30%
• B) statistically significant findings in both the clinical setting and at home
• C) evidence of a consistent effect in the winter and the spring
• D) evidence that shows SAT scores and GPA change with improved study habits

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Definitions:

Carbon Dioxide

A colorless, odorless gas produced by burning carbon and organic compounds and by respiration. It is naturally present in the air and absorbed by plants in photosynthesis.

Iron

A metallic element (Fe) that is vital for biological processes in humans and other organisms, such as oxygen transport and cellular metabolism.

Scrap Metal

Waste metal materials that can be recycled and reused, often collected from leftover products, buildings, or discarded industrial machinery.

Energy

The capacity to do work, manifest in forms such as heat, light, motion, and chemical bonds, essential to human society for various applications.