PARTICIPATION 11.4 Observational studies and experiments. ACTIVITY 1) Count and size data for trout and salamanders were collected from two types of forest areas, clear-cut and old growth. Data has been collected yearly 1987-2019. This data was collected through an O experiment O observational study 2) Collecting data on happiness and money by giving a five-question survey to individuals in a downtown area would be collecting data through an O experiment O observational study​