D.3 Answers: Research designs
Answers to exercises in Sect. 3.10.
Answer to Exercise 3.1:
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.
Answer to Exercise 3.2:
The researchers had no say in who was in hospital at the time:
they could not allocate the patients to the two groups (overlay; matress).
this is a quasi-experiment.
Answer to Exercise 3.3:
1. P: Perhaps people in a suburb of the Sunshine Coast;
O: 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.
Answer to Exercise 3.4:
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 individuals: those from whom the weight change is taken.
5. The individuals: the diets are allocated to each individual.
6. The change in body weight over two years.
7. The type of diet.