How Might the Selection of Groups in Observational Studies Affect

question 15

Multiple Choice

How might the selection of groups in observational studies affect the construct validity of the study?

• A) Populations sampled from might be too general
• B) Populations sampled from might not be representative
• C) Subjects' status on the characteristic of interest might vary systematically
• D) Subjects might show random variation on other characteristics of interest

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Definitions:

RFID Tag

A technology that uses electromagnetic fields to automatically identify and track tags attached to objects, containing electronically stored information.

RFID

Radio Frequency Identification, a technology used to transmit data wirelessly using electromagnetic fields to identify and track tags attached to objects.

Bar Codes

A machine-readable code in the form of numbers and a pattern of parallel lines used to identify a product.

Wireless Sensor

An autonomous device that monitors its own condition as well as physical and environmental conditions around it, such as temperature, sound, pressure, vibration, and movement.