Mini-Exam 3-SACR 3080, chapters 10,11,12,13
questions with verified answers already passed
1. What is an In this interpretation, gamma is said to provide the excess of
interpreta- tion of concordant over discordant pairs (or vice versa) as a proportion
gamma that is not of all such pairs
PRE?
2. What is the differ-
A symmetric measure gives us the same result whichever
ence between a
variable is treated as independent. Examples include gamma and
sym-
r. An asymmetric
metric and an asymmet- measure gives ditterent results, depending on which
variable is treated
ric measure of as independent. Examples include lambda, and d.
associa- tion? Give
an example of each.
3. Why do we use Q or Q and the Odds Ratio are based entirely on the relations between
the ODds Ratio to cell values within a table (the inner structure), so they can
compare two 2x2 be compared across tales with dittering marginal totals.
tables?
r = Cov(x,y) / SD(x)SD(y). This turns into the sum of zxzy/N
4. Give the formula
In words this is the mean of the products of the standardized
for r that does variables.
not use algebraic
notation. If
we standardize the
vari- ables, what
does the for- mula
turn into? The rectangles are of ditterent sizes because their areas are
proportional
5. In a mosaic plot, why
are the rectangles of dif- to the number of cases in the cells represented. The
Pearson residuals
ferent sizes? Why do R calls the Pearson residuals?
we care about what
1/
6
, Mini-Exam 3-SACR 3080, chapters 10,11,12,13
questions with verified answers already passed
6. In analyzing cross can be used to identify cells that are unusually heavy or light.
tab- ulations, what
do we mean by
Distortion? Give an
example. Distortion exists when the relationship between variables is
reserved when we control for a third "lurking" variable, without
which we cannot see the meaningful link between the first two.
The textbook example was a study in which smokers died more
often than non-smokers, and in which controlling for age
showed smokers dying more often .
2/
6
questions with verified answers already passed
1. What is an In this interpretation, gamma is said to provide the excess of
interpreta- tion of concordant over discordant pairs (or vice versa) as a proportion
gamma that is not of all such pairs
PRE?
2. What is the differ-
A symmetric measure gives us the same result whichever
ence between a
variable is treated as independent. Examples include gamma and
sym-
r. An asymmetric
metric and an asymmet- measure gives ditterent results, depending on which
variable is treated
ric measure of as independent. Examples include lambda, and d.
associa- tion? Give
an example of each.
3. Why do we use Q or Q and the Odds Ratio are based entirely on the relations between
the ODds Ratio to cell values within a table (the inner structure), so they can
compare two 2x2 be compared across tales with dittering marginal totals.
tables?
r = Cov(x,y) / SD(x)SD(y). This turns into the sum of zxzy/N
4. Give the formula
In words this is the mean of the products of the standardized
for r that does variables.
not use algebraic
notation. If
we standardize the
vari- ables, what
does the for- mula
turn into? The rectangles are of ditterent sizes because their areas are
proportional
5. In a mosaic plot, why
are the rectangles of dif- to the number of cases in the cells represented. The
Pearson residuals
ferent sizes? Why do R calls the Pearson residuals?
we care about what
1/
6
, Mini-Exam 3-SACR 3080, chapters 10,11,12,13
questions with verified answers already passed
6. In analyzing cross can be used to identify cells that are unusually heavy or light.
tab- ulations, what
do we mean by
Distortion? Give an
example. Distortion exists when the relationship between variables is
reserved when we control for a third "lurking" variable, without
which we cannot see the meaningful link between the first two.
The textbook example was a study in which smokers died more
often than non-smokers, and in which controlling for age
showed smokers dying more often .
2/
6
