Question

Do Left-Handers Die Earlier? According to a study published in the Journal of the American Public Health Association, lefthanded people do not die at

Study design
ANSWERED
asked 2020-11-05
Do Left-Handers Die Earlier? According to a study published in the Journal of the American Public Health Association, lefthanded people do not die at an earlier age than right-handed people, contrary to the conclusion of a highly publicized report done 2 years earlier. The investigation involved a 6-year study of 3800 people in East Boston older than age 65. Researchers at Harvard University and the National Institute of Aging found that the “lefties” and “righties” died at exactly the same rate. “There was no difference, period,” said Dr. J. Guralnik, an epidemiologist at the institute and one of the coauthors of the report.

Answers (1)

2020-11-06
Step 1
Observational study:
The investigators may simply observe a predefined set of individuals and collect the data from the observations, without influencing any factors involved. This is an “observational study”.
Designed experiment:
The investigator may design and perform their own experiments my controlling and manipulating factors of their choice and collect the resulting data. This is the “designed experiment”.
Step 2
The investigators had no influence on whether an individual was left-handed or right-handed. The investigators could simply observe the individuals and form a conclusion from their observations.
Thus, the investigation is an observational study.
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