Unit 13

Question 1

If the correlation coefficient between two variables, A and B, is near 0 then

Answer 1

The two variables may be statistically related, but not in a linear way

Question 2

What is the minimum requirements for a table lens?

Answer 2

One categorical variable and 2 or more quantitive variables

Question 3

Correlations are described by:

Answer 3

Direction
Shape and
Strength ??

Question 4

Suppose you have three quantitive variables: patient satisfaction score of their provider, patient age, their provider’s age. You would like to examine whether differences or similarities in the age of the patient and provider relate to the patient satisfaction score. What is the best graph for exploring this relationship?

Answer 4

x: physician age - patient age, y: patient rating

Question 5

Determine whether age at diagnosis, tumor size at diagnosis, and survival might be related
Scatterplot Matrix

Determine whether age at diagnosis, and tumor size at diagnosis might be related
Scatterplot

Answer 5

Determine whether there may be a relationship between age at diagnosis, tumor size at diagnosis, and survival for several different types of cancer
Table Lens

Determine whether the sequence of treatment events affects survival rate
Temporal

Question 6

Correlation analysis should be used as:

Answer 6

NOT identify trends, final confirmation

MAYBE?
For preliminary assessment of unknown datasets
To improve existing plots

Question 7

Suppose you have four quantitive variables for each country: annual health expenditures per capita, average life expectancy at birth, average infant mortality per 1000 births, average birth rate. if you want to examine all pairwise relationships between each of the four variables, what is the best graph?

Answer 7

A scatterplot matrix

Question 8

You suspect that tumor size at diagnosis may affect survival time and that male patients may differ from female. What should you plot to examine this relationship?

Answer 8

x: tumor size, y: survival time, color: two distinct hues (one for male and one for female)

Question 9

The following graph looks at survival time of women with ovarian cancer (futime) vs. their age at study onset.

Suppose you swap the variables above by plotting age on the x axis and futime on the y axis. What would happen to the correlation?

Answer 9

The correlation would not change

Question 10

The following graph looks at survival time of women with ovarian cancer (futime) vs. their age at study onset.

Given only the data in the graph above, what is the most accurate description of the relationship between the variables age and futime?

Answer 10

age and futime have a weak negative correlation
- The correlation is negative because as one variable increases, the other decreases. The correlation is weak because most of the points fall far from the regression line

Question 11

Which of the following can be treated as a method of analytical interaction:

Answer 11

Re-expressing
Annotating
Aggregating
All of above

Question 12

Select the most accurate statement about adding variables

Answer 12

In order to get a better perspective or context or to greater realize a potentially strong connection, we might need to add an additional variable

Question 13

Suppose you have the following data in Excel:

and you would like to produce the following graph:

What is the best way to do this in Tableau?

Answer 13

Use a dual axis display

NOT!!Select both Actual Readmissions and Readmission Goal in the measures pane and then click Show Me’s side-by-side bars icon
-This will not work unless you also select Date

Question 14

When constructing information visualizations, which of the following should you support?

Answer 14

-Overview first
- Zoom and filter
- Details on demands
All of above

Question 15

Moving average is __

Answer 15

Re-expressing
aggregating