In the study being a smoker is the factor and having heart disease is the. Two examples of on-site observational studies with older persons. Types Of Epidemiology Studies Cohort Study Research Methods Nursing School Studying An observational study they simply observe what the participants do naturally. . This study used a controlled observation to assess infants type and quality of attachments with their mothers. Dividing a class into thirds giving each third a different amount of time to read and then testing comprehension B. To find out whether car accidents are more likely on rainy days a researcher records the weather conditions during 50 randomly selected accidents for the past year. The situation is an example of an observational study. Asking voters about the candidate they prefer C. The definition of an observation is the act of noticing something or a judgment or inference from something seen or experienced. ...