Research studies are conducted in order to answer some kind of research question(s). For example, the researchers in the Vegan Health Study define at least eight primary questions that they would like answered about the health of people who eat an entirely animal-free diet (no meat, no dairy, no eggs). Another research study was recently conducted to determine whether people who take the pain medications Vioxx or Celebrex are at a higher risk for heart attacks than people who don't take them. The list goes on. Researchers are working every day to answer their research questions.
What do you think about these research questions?
- What percentage of college students feel sleep-deprived?
- What is the probability that a randomly selected PSU student gets more than seven hours of sleep each night?
- Do women typically cry more than men?
- What is the typical number of credit cards owned by Stat 414 students?
Assuming that the above questions don't float your boat, can you formulate a few research questions that do interest you?
If we were to attempt to answer our research questions, we would soon learn that we couldn't ask every person in the population if they feel sleep-deprived, how often they cry, or the number of credit cards they have.
Try It! Section
How can we answer our research question if we can't ask every person in the population our research question?
We could take a random sample from the population, and use the resulting sample to learn something about the population.