Explain why the Harvard Nurses’ Health Study is an observational study.
Chapter One
1) Determine whether the evaluated group is a population or a sample
- a) Based on a randomly selected group of 500 patients with high cholesterol, it was found that 67% have heart disease. Is this a population or a sample; explain your answer.
- b) An investigation of 150 randomly selected local restaurants concluded that 42% of local restaurants have serious health code violations. Is this a population or a sample; explain your answer.
2) Determine whether the given value is a statistic or a parameter.
- a) A researcher determines that 42.7% of all downtown office buildings have ventilation problems. Is this a statistic or a parameter; explain your answer.
- b) After taking the first exam, 15 of the students dropped the class. Is this a statistic or a parameter; explain your answer.
3) Identify the type of sampling used.
- a) A tax auditor selects every 1000th income tax return that is received. What type of sample is this and why?
- b) The name of each contestant is written on a separate card, and the cards are placed in a bag with three names being picked from the bag. What type of sample is this and why?
4) Is the study experimental or observation and why?
- a) A political pollster reports that his candidate has a 10% lead in the polls with 10% undecided.
5) Select the study that is most appropriate and EXPLAIN WHY it is most appropriate for the study.
- a) Is the aspirin produced by a particular pharmaceutical company better than that of a competitor at relieving headaches? Which of the following would best be used to study this: 1) a case-controlled observation; 2) an observation; 3) a double-blind experimental procedure; and 4) and experimental procedure.
From Chapter One
1) Focus on Public Health—On page 44 of the text, it discusses the Harvard Nurses’ Health Study, which is a very well-known study that has been conducted for a number of years. Answer discussion question two at the end of the article.
Explain why the Harvard Nurses’ Health Study is an observational study. Critics sometimes say that the results would be more valid if obtained by experiments rather than observations. Discuss whether it would be possible to gather similar data by carrying out experiments in a practical and ethical way.