ASSIGNMENT 1: ABORTION DATA
KEY FINDINGS
(1) The most common restriction is Parental Involvement, followed by
Waiting Period and Insurance Coverage.
(2) It is less likely that only one restriction applies. Only 7 out of 8 possible
combinations of restrictions exist. “None” is the most likely combination.
Restrictions are dependent as ‘yes’/’yes’ and ‘no’/’no’ combinations are
more likely than ‘yes’/’no’ combinations.
(3) Restrictions can be ranked according to their association with abortion rate
a. Strong association between Parental Involvement and abortion rate
b. Weaker association between Waiting Period and abortion rate
c. Almost no association between Insurance Coverage and abortion rate
(4) Definition of abortion rate:
Abortions per 1000 women aged 15-44 might be questioned towards:
a. Location where abortion took place rather than residence
b. Denominator should rather be per live birth or pregnancy
(5) Demographic variables associated with abortion:
a. Population
b. Wages
c. Employment
d. Urbanity
e. Education
f. Religion
(6) [Geographic reference via maps]
GENERAL REMARKS ON DATA ANALYSIS AND REPORT WRITING
(1) When talking about summaries in the text, actually write down the values!
(2) Group sizes should be expressed in terms of proportions but not absolute
numbers.
(3) Express summaries and models in terms of sensible units. Sometimes 1 $ is
sensible, sometimes 1,000$.
(4) Place tables and graphics in the main body of the report, close to where you
refer to them in the text.
(5) When building groups or hierarchies, stick to proven standards.
E.g. for demographic data the US bureau of census is the “golden standard”
(6) The layout of a table strongly impacts its readability:
a. Keep values you want to compare close together
b. Sort rows/columns according to entries in the table
c. Build hierarchies on columns and rows
d. Tables work well for comparing statistics/summaries for different
subgroups, but usually fall short of interpreting associations.
(7) Graphical comparison of location measures:
For skewed distributions:
mode < median < mean
or
mean < median < mode
For small samples only the median is somewhat robust
Parallel Boxplots usually do a better job:
(8) Use additional data to support your analysis, but
a. make sure not to ignore the initial data
b. reference your data carefully and/or attach your data
c. make sure the data is correct
(if data isn’t correct, at least make sure you are the first to find out!)
(9) Closely match Questions and Answers:
a. Make sure you address all the initial questions first
b. Match questions not methods
c. Do not use external knowledge
d. Avoid stating your personal opinions