Final answer:
Descriptive studies involve observational methods to collect data without manipulating variables. They provide a snapshot of natural phenomena, aiding in understanding behaviors or conditions, but their ability to generalize is limited.
Step-by-step explanation:
Descriptive studies, often used in human biology research, are a type of observational study. These studies involve measuring characteristics in a sample without attempting to manipulate variables. For instance, in a political poll, which is a simple observational study, researchers might collect data on age and political preference from a sample of adults. The results provide insight into voter opinions at a particular moment in time, and whether these results generalize to the entire population depends on the sample size and randomness.
Researchers might conduct case studies, which are detailed examinations based on observations of individuals or groups. The findings from case studies are interpreted within a limited context, usually with the aim of identifying paths for further research rather than making broad generalizations. Case studies rely on qualitative research, which involves collecting subjective evidence that is difficult to control and replicate, such as observing behaviors in a classroom or hospital.
Sometimes, when experimental studies are not feasible or ethical, observational studies can be used to explore relationships without directly manipulating the independent variable. For example, if researchers wanted to study the effect of malnutrition on school performance, they would record and measure naturally occurring phenomena rather than inducing malnutrition. In contrast, a survey would involve data collection through questionnaires filled out by participants.
Overall, descriptive studies provide a snapshot of naturally occurring phenomena, which can lead to a deeper understanding of certain behaviors or conditions, albeit with limitations regarding the ability to generalize findings to a larger population.