Homework Assignment #1

All homework assignments must typed or legibly handwritten, and must show your name, the assignment number, course number, and the date clearly.  Homework is due at the beginning of class on the specified date.

Exercises in text:

Chapter 1: #2, 10, 18

Chapter 5: #15

Other exercises:

Indicate which scale of measurement (nominal, ordinal, or interval) each of the following represents and explain why.  The variable's values or units of measurement are in parentheses.

1. attitude toward legalization of marijuana (favor, neutral, oppose)
2. number of siblings (0, 1, 2, etc.)
3. habitat (wetland, prairie, tundra, desert, etc.)
4. political philosophy (liberal, moderate, conservative)
5. weight at birth (in whole grams)
6. sex (male, female)

List the highest scale could be used to measure each of the following variables.  For each scale you list, suggest a few possible values or units of measurement.

7. sexual orientation
8. volume (of a liquid)
9. race/ethnicity
10. highest educational degree obtained

11. A researcher is interested in estimating the average age at marriage for women in New England in the early 18th century.  She finds within her state archives reasonably complete marriage records for a large Puritan village for the years 1700-1730.  She selects some of these records to examine for her study, noting the age of the bride for each.  What is this study's sample?  What is the population of interest?  Does this coincide with the population to which generalizations can reasonably be made from this study?  If no, what is this latter population?

12. Go to the Survey Documentation and Analysis (SDA) web site (http://csa.berkeley.edu:7502/archive.htm).  Also put this site in your browser's bookmarks or favorites.   Under the "National Omnibus Surveys," click on "GSS Cumulative Datafile 1972-1996." This retrieves information about and data from the General Social Survey, a multistage cluster probability sample survey of adults living in U.S. households.  The next screen should read "SDA Demonstration Survey Data Archive."  Select the " Browse codebook in this window" option and then hit the "Start" button 2/3 of the way down the screen (not the Windows button with the Microsoft Windows icon) to get information about all of the variables in the data set.

After the next screen appears, click on "Group Headings" on the left side of the screen and then scroll down this outline of question topics until you come to "Obligations and Responsibilities."  Click on "Civic Obligations."  The next screen shows a table with the name of civic obligation-related variables in the GSS (these variable names will never be longer than 8 characters) and a summary of the question content.  Click on the "obvote" variable.  Scroll down just a little on the resulting screen, and look under the "Label" column.  These labels are the response options to the survey question.

a) List the response options.
b) Indicate the scale (nominal, ordinal, interval) with which the OBVOTE variable was measured and explain your classification.  (For classifying variables by scale of measurement, ignore the codes for "DK" [don't know], "N/A" [not applicable], and no data).

Using your browser's "Back" button, go back to the "Group Headings" screen with the outline of variables.  Go through the outline and find a category that interests you.  Select a variable and then:

c) List the name of the variable, the summary of the question, and the response options.
d) Indicate the scale (nominal, ordinal, interval) with which the variable was measured and explain your classification.

13. In a laboratory experiment, a researcher exposed a sample of butterflies to pollen from corn (in some areas, butterflies live near cornfields).  She randomly assigned each butterfly to one of two groups.  One group was exposed to the pollen from corn that had been genetically modified to produce a substance that repelled pests.  The other group was exposed to the pollen of corn that had not been modified in this way.  The results showed that the vast majority of the butterflies in the genetically modified corn pollen group died soon after exposure, while most of the butterflies in the control group survived.  She concluded that the pollen from genetically modified corn was toxic to butterflies and that such corn should be banned.  Several months later, other researchers conducted a experiment in which they compared survival rates for butterflies in cornfields that had been randomly assigned to grow genetically modified or non-modified corn.  They found that the butterflies in the fields growing genetically modified corn were only slightly more likely to die than butterflies in the fields growing non-modified corn.  Explain why the two experiments produced such different results.