## 2.13 Exercises

Selected answers are available in Sect. D.2.

Exercise 2.1 In a study of public acceptance of alternative water supplies , various water sources are defined. In Table 2.5, match the term with the appropriate operational definition.
TABLE 2.5: Match the term with the operational definition
Term Definition
Rainwater Rainwater from a rainwater collection tank on your property
Bottled Water you presently use throughout your dwelling (home)
Tap Highly purified seawater deemed by scientists and public health officials as safe for human consumption.
Recycled Highly purified wastewater deemed by scientists as safe for human consumption
Desalinated Water sold in bottles by food companies that is widely available to the public for purchase and consumption

Exercise 2.2 Consider this RQ:

Among USC students, is the average resting diastolic blood pressure the same for students who regularly drive to USC and those who regularly ride their bicycles?

1. For this RQ, identify the Population.
2. For this RQ, identify the Outcome.
3. For this RQ, identify the Connection, if any.
4. For this RQ, identify the Intervention, if any.
5. What type of RQ is this?
6. What operational definitions would be needed?
7. What information must be collected from each individual to answer the RQ?
8. What are the units of analysis?
9. What are the units of observation?

We conducted a 4-year (1995–1998) field study in a Peruvian peri-urban community… to examine the relation between diarrohea and nutritional status in 230 children $$<3$$ years of age

, p. 210

For this study:

1. Identify PICO.
2. Infer the primary research question.
3. What type of question is used?
4. What operational definitions would be needed?
5. What are the response and explanatory variables?

Exercise 2.4 For the following response variables, what would be the corresponding outcomes?

1. Whether a vehicle crashes or not.
2. The height at which people can jump.
3. The number of tomatoes per plant.
4. Whether or not a person owns a car.

Exercise 2.5 For the following comparisons, what would be the corresponding explanatory variables?

1. Between 91 octane, 95 octane, and ethanol-blended car fuel.
2. Between caffeinated and decaffeinated coffee.
3. Between taking zero, one or two iron tablet per day.
4. Between vegans and vegetarians.

Exercise 2.6 For the following studies, determine which have a Comparison and which do not. In each case, identify the Outcome.

1. A study to determine if a higher percentage of people at a particular city park wear hats in winter compared to summer.
2. A study to determine if average cholesterol levels are the same when measured on the same people before and after a diet change.
3. A study to determine if the average balance-time on right legs is the same as on left legs.
4. A study to determine if the average yield of tomato plants is the same when three different fertilisers are applied.

Exercise 2.7 Animals in an experiment are divided into pens (three per pen), and feed is allocated to each pen . Animals in different pens receive different feed; animals in the same pen receive the same feed. The weight gain of each animal is recorded.

1. What is the unit of observation? Why?
2. What is the unit of analysis? Why?

Exercise 2.8 Consider this actual Project Report RQ. Critique the RQ, and write a better RQ (if necessary).

Among 10 Australian adults, does the time taken to read a passage of text change when different fonts are used?

Exercise 2.9 Consider this actual Project Report RQ. Critique the RQ, and write a better RQ (if necessary).

Of students that study at USC, Sippy Downs, do males have a larger lung capacity than females?

### References

Checkley W, Gilman RH, Black RE, Lescano AG, Cabrera L, Taylor DN, et al. Effects of nutritional status on diarrhea in Peruvian children. Journal of Pediatrics [Internet]. 2002;140(2):210–8. Available from: http://www.ncbi.nlm.nih.gov/pubmed/11865273.
Hurlimann A, Dolnicar S. Public acceptance and perceptions of alternative water sources: A comparative study in nine locations. International Journal of Water Resources Development. 2016;32(4):650–73.
Sterndale SO, Miller DW, Mansfield JP, Kim JC, Pluske JR. Increasing dietary tryptophan and decreasing other large neutral amino acids increases weight gain and feed intake in weaner pigs infected with escherichia coli. Animal Production Science. CSIRO; 2017;57(12):2410–0.