Question

Which of the following describe an observational study? Check all that apply.

Group of answer choices

Study 1: An early study of the relationship between smoking and lung cancer was conducted by Hammond & Horn (1958). They had an extensive set of volunteers track 187,766 men over a 44-month period, noting their smoking habits and whether or not they had died of lung cancer.

Study 2: A study published in the Archives of Internal Medicine reported on the effectiveness of a nicotine lozenge for smokers who wanted to quit (Shiffman et al., 2002). The researchers assigned one group of smokers to receive a nicotine lozenge and another group of smokers to take a placebo lozenge with no active ingredient. They compared the proportion of smokers who successfully quit smoking in each of the two groups.

Study 3: Researchered assigned people to one form of acupuncture treatment (some people received a traditional form of Chinese acupuncture, others received fake acupuncture, and some people received conventional treatment). They compared the proportion of people in each group who improved in their chronic back pain.

Study 4: In a recent study (Klein, Thomas, & Sutter, 2007), researchers found that current smokers were more likely to have used candy cigarettes as children than current nonsmokers were.

Answer 1

study 1 : OBSERVATIONAL it is a Observational study as they are observing the smoking habbits abd noting ehether or not they had died of lung cancer

study 2 : this is Experimental study .as they are experimenting the effectivness of the nicotine lozenge for smokers

study 3 : this is Experimental study as here treatment is going to be assigned to the people

study 4 : OBSERVATION this is observational study. as researchers observed that current smokers were more likely to have used candy cigarettes as children than current nonsmokers were