Adapted from Dunn (2021).
The researchers could decide which beams go into Group A and into Group B. Researchers could also allocate treatments to the groups: they could select what treatments is applied to each group of beams. This is a true experiment.
The researchers had no say in who was in hospital at the time: they could not allocate the patients to the two groups (overlay; mattress). This is a quasi-experiment.
1. P: Perhaps people in a suburb of the Sunshine Coast; O: average number of doctor’s visits in the next six months; C: between people owning a pet for those six months, and those who do not own a pet for those six months. 2. For an experiment, we would need to intervene to give subjects a pet, or not give them a pet. 3. For an observational study, we would not intervene: We would find the subjects who already owned a pet, or who did not already own a pet.
1. P: A bit vague from this small extract: people of some kind; O: the average change in body weight over two years; C: Between the four diets; I: The diets seems to be have been imposed. 2. Experimental: The diets have been imposed by the researchers, with the intent of changing the outcome (the weight change). 3. Probably a true experiment. 4. The change in body weight over two years. 5. The type of diet.
These notes have been prepared by Amanda Shaker. The copyright for the material in these notes resides with the authors named above, with the Department of Mathematics and Statistics and with La Trobe University. Copyright in this work is vested in La Trobe University including all La Trobe University branding and naming. Unless otherwise stated, material within this work is licensed under a Creative Commons Attribution-Non Commercial-Non Derivatives License BY-NC-ND.