1.1 Cargo cult science. Read the passage below. Then describe in one page or less a cargo cult measurement or study you are aware of.
The unorthodox scientist Richard Feynmann used the term Cargo Cult Science to refer to pseudoscientific practices that follow the superficial forms and precepts of science but miss the honest, self-critical element that is crucial to rigorous investigation. This term has it basis in a South Seas people that, during World War II, saw airplanes land with goods and materials. They inhabitants of the island wanted these deliveries to continue after the military had left, so they arranged to imitate things they saw associated with the cargo, like the runways lights (in the form of fires), a wooden hut for a "controller" who wore two wooden pieces on his head to emulate headphones, bamboo sticks to imitate antennas, and so on. With the Cargo culture in place, the island inhabitants awaiting airplanes to land. The form was right--on the surface things looked as they had before--but of course things no longer functioned as they had hoped. Airplanes full of cargo failed to bring goods and services.
1.2 Oral contraceptives and breast cancer. A study of 135,000 post-menopausal women between the ages of 50 and 70 found no difference in the incidence of breast cancer in oral contraceptive users and non-users. What population is being studied in this investigation? Is the population restricted to the 135,000 study participants?
1.3 Hospital duration data (HDUR). A study used the discharge records of 30 patients from a university hospital in metropolitan Detroit to find that 35% of patients received antibiotics during their hospital stay. Describe the population and sample for this study.
1.4 Body weight expressed as a percentage of ideal (%IDEAL). A study of eighteen 35- to 44-year old male diabetics found that mean body weight was 13% above ideal. Describe the population and sample for this study.
1.5 Teaching effectiveness. College administrators are concerned with evaluating the effectiveness of classroom instruction. One method used for this purpose is to ask students to rate various facets of their classes. One question asks students to rate the overall effectiveness on a 5-point scale with 5 representing "highly effective" and 1 representing "very ineffective." Discuss the limitations of this method of measuring teaching effectiveness. In so doing, consider how you would define "teaching effectiveness." Does the variable in question measure teaching effectiveness or something else?
1.6 Dietary fat consumption. In studying dietary fat consumption, prospective studies may ask study participants to keep daily logs of their dietary habits. In contrast, retrospective studies must rely on the recall of study participants to remember what and how much they ate. Which method of measuring dietary is more likely to achieve valid results, prospective dietary logs or retrospective recall? Explain you reasoning.
1.7 Duration of hospitalization (HDUR) Data below are a subset from a study on antibiotic usage and other factors from patients at general hospitals in Pennsylvania. Information on the following variables are available:
Variable Description
---------- -----------------------------------
DUR Duration of hospitalization (days)
AGE Age (years)
SEX 1 = male 2 = female
TEMP Body temperature (degrees Fahrenheit)
WBC White blood cells per 100 ml blood
AB Antibiotic use: 1 = yes 2 = no
CULT Blood culture taken 1 = yes 2 = no
SERV Service: 1 = medical 2 = surgicalHere are 25 records from this data set:
ID DUR AGE SEX TEMP WBC AB CULT SERV
-- --- --- --- ----- --- -- ---- ----
1 5 30 2 99.0 8 2 2 1
2 10 73 2 98.0 5 2 1 1
3 6 40 2 99.0 12 2 2 2
4 11 47 2 98.2 4 2 2 2
5 5 25 2 98.5 11 2 2 2
6 14 82 1 96.8 6 1 2 2
7 30 60 1 99.5 8 1 1 1
8 11 56 2 98.6 7 2 2 1
9 17 43 2 98.0 7 2 2 1
10 3 50 1 98.0 12 2 1 2
11 9 59 2 97.6 7 2 1 1
12 3 4 1 97.8 3 2 2 2
13 8 22 2 99.5 11 1 2 2
14 8 33 2 98.4 14 1 1 2
15 5 20 2 98.4 11 2 1 2
16 5 32 1 99.0 9 2 2 2
17 7 36 1 99.2 6 1 2 2
18 4 69 1 98.0 6 2 2 2
19 3 47 1 97.0 5 1 2 1
20 7 22 1 98.2 6 2 2 2
21 9 11 1 98.2 10 2 2 2
22 11 19 1 98.6 14 1 2 2
23 11 67 2 97.6 4 2 2 1
24 9 43 2 98.6 5 2 2 2
25 4 41 2 98.0 5 2 2 1
(A) Classify each variable's as either quantitative, ordinal, or categorical.
(B) What is the value of the DUR variable for observation 4?
(C) What is the value of the AGE variable for observation 24?
1.8 Clustering of an adverse drug event (TOXIC). An investigation was prompted when the U. S. Food and Drug Administration received a report of an increased frequency of cerebellar toxicity from the University of Wisconsin Hospital and Clinics (Madison) after the hospital had switched from the product manufactured by the innovator company (Upjohn, Co., Kalamzoo, MI) to a generic product produced by Quad Pharmaceuticals, Inc. (Indianapolis, IN). To address this issue, the FDA sent a team of investigators to complete a chart review. Data on patient and treatment characteristics that may place patients at greater risk for toxic reactions was collected. Variables included:
Variable Description
---------- -------------------------------------------------
AGE Age at time treatment began (years)
SEX 1 = male; 2 = female
MANUF Manufacturer of the drug: Smith or Jones
DIAG Underling diagnosis: 1 = leukemia; 2 = lymphoma
STAGE Stage of disease: 1 = relapse; 2 = remission
TOX Did cerebellar toxicity occur?: 1 = yes; 2 = no
DOSE Dose of drug (grams /meters2)
SCR Serum creatinine (mg/dl)
WEIGHT Body weight (kg)The first 5 records (observations) in the data set look like this:
ID AGE SEX MANUF DIAG STAGE TOX DOSE SCR WEIGHT
--- --- ----- ------ ----- ----- --- ------ ------ ------
1 50 1 J 1 1 1 36.0 0.8 66
2 21 1 J 1 2 2 29.0 1.1 68
3 35 1 J 2 2 2 16.2 0.7 97
4 49 2 S 1 1 2 29.0 0.8 83
5 38 1 J 2 2 1 16.2 1.4 97
(A) Classify each variable's as either quantitative (scale), ordinal, or categorical (nominal).
(B) What is the value of the AGE variable for observation 4?
(C) What is the diagnosis of observation 2?
1.9 Variable types 1. Classify each of the following measurements as either quantitative (scale), ordinal, or categorical (nominal).
1.10 Variable types 2. Classify each of the following measurements as quantitative (scale), ordinal, or categorical (nominal).
Key to Odd Numbered Problems Key to Even Numbered Problems [Keys may not be posted at the discretion of the author]