Final answer:
Observational studies involve observing and recording data without manipulating variables, commonly used when experiments are not ethical or feasible. They help identify correlations, but cannot confirm causation.
Step-by-step explanation:
What Happens in Observational Studies?
In observational studies, researchers do not manipulate the independent variable. Instead, they collect data and measurements from naturally occurring phenomena. Control and experimental conditions are derived from these observations to examine the relationship between the dependent and independent variables. Observational studies can take the form of case-control, cross-sectional, or cohort studies, and they are commonly used when experimental studies are not ethical or feasible.
For instance, to investigate the impact of aspirin on heart attack risk, researchers might conduct a study where some individuals take aspirin and others take a placebo without knowing which one they receive. Such a study allows scientists to observe outcomes without influencing the variables. Surveys are another form of observational research, where participants respond to questionnaires, providing data on various variables.
While observational studies are useful for identifying correlations—such as a positive correlation between smoking and lung cancer risk, or a negative correlation between exercise and lung cancer—they do not establish causation. Unlike experimental studies, where all variables are controlled to determine causality, observational studies do not manipulate variables and therefore can only suggest associations.