An observational study is a type of research where the investigator observes subjects and measures variables of interest without assigning treatments to the subjects. This approach is often used when randomized controlled trials are not feasible or ethical, allowing researchers to draw conclusions about associations and potential causal relationships based on naturally occurring variations.
Correlation measures the strength and direction of a linear relationship between two variables, with values ranging from -1 to 1, where 1 indicates a perfect positive relationship, -1 a perfect negative relationship, and 0 no relationship. It is crucial to remember that correlation does not imply causation, and other statistical methods are needed to establish causal links.
Baseline data collection is the initial step in research or project planning, where data is gathered before any intervention or change is implemented. This data serves as a reference point for measuring the impact or effectiveness of future actions or interventions.