Question

To study U.S. physicians, researchers surveyed 24,216 of them and asked for the following information below. (source: Medscape from WebMD)

gender (male or female)
location (region in the US)
age (number)
income (number)
location of work (hospital, group practice, etc.)
specialty (cardiology, family med, radiology, etc.)
hours seeing patients per week (number)
number of patient visits per week (number)

a) Identify the population and the sample. (2 points)
b) Are the data collected qualitative, quantitative, or both? Explain. (3 points)
c) Determine the level of measurement for each item above. (4 points)
d) Determine whether the study is an observational study or experimental. Explain. (2 points)

Answer 1

(a)

The population for the experiment conducted consist of all physicians in the U.S. and the sample consist of 24,216 physicians out of all the physicians in the U.S.

(b)

The data collected for the experiment is both qualitative and quantitative in nature, as the data on age, income, hours seeing patients per week and number of patients visiting per week are quantitative, and the data collected on specialty are qualitative in nature.

(c)

The levels for each item considered in the success are given as follows:

Gender is a nominal variable because in a nominal variable there can be two or more categories without having any specific order. Gender also has two categories, male and female, and male and female are not ordered.

Location is a nominal variable as there can be many locations without any order.

Age is an interval variable. An interval variable is a quantitative variable in which two variables can be compared. For example, suppose there are two physicians. The age of the first physician is say 35 years and the age of the second physician is say 40 years, then we can say that the second physician is 5 years older than the first physician.

Income is an interval variable as an interval variable is a quantitative variable and the difference between any two variables is meaningful. Suppose there are two physicians and the salary of one physician is say \(\$ 30,00\) and the salary of another physician is say \(\$ 40,000\). So, it can be said that the second physician is earning \(\$ 10,000\) more than the first physician.

Location for work is also a nominal variable as there can be several locations to work for a physician.

Specialty is a nominal variable as there are many specialties in which a physician can be master, but these specialties cannot be ordered.

Hours seeing patients per week is a ratio variable. In the ratio variable, zero has true meaning. Here, if a physician is absent for a week, this implies that he spent zero hours for seeing any patient in a week.

The number of patients visiting per week is also a ratio variable as there may be a situation when no patient visits doctor for checkup.

(d)

The study conducted on the physicians of the U.S. is an observational study as in observational study, the researcher simply collects the data and draw results on the basis of the data collected. Also, the researcher cannot add any data or extra information while performing an observational study. Here also, in this study, the researcher has collected the data from physicians, no data is being added by the researcher in the data collected.

Therefore, the study conducted is an observational study.