Additional areas in the guidance are considered <u>“required reading”</u> for a researcher who has found general guidance in the Initial Measurement section include:
Implementation Guidance
SEC Guidance
Initial Measurement Section
Answer: They are useful when a researcher is attempting to STUDY PEOPLE OR SITUATIONS THEY MIGHT NOT OTHERWISE HAVE ACCESS TO.
As can be inferred from the definition of Observational study, in which it is a research that the researcher have no control/influence over due to logistical restrictions or ethical reasons. This means that they will be especially useful when the researcher have no access to the participants.
The underlying reason was that the white population which did not agree with African Americans voting tried to find other ways of preventing them from doing it. This included poll tax, introducing educational and character requirements and introducing other obstacles.
the lithosphere of the earth is divided into a small number of plates which float on and travel independently over the mantle and much of the earth's seismic activity occurs at the boundaries of these plates.
hope this helps :)