Q10 Visuals Flashcards
Nominal variables cannot . . .
Add to 100 because they are categories
Mixing sources
Makes a total of 100% anticlimactic
Where do words align on a table?
The left
Where do numbers align?
- The right
- Decimal points MUST align
For a table with percentages, first find out . . .
Whether the rows or columns add to 100%
“66% of US Jews” invokes . . .
(Portion/Whole) x 100 Formula
Can you add two percentages for one category’s result in a table to find the total of answers for that category?
No, because the two numbers just show the maximum and minimum percentage, meaning the total is between the two
How can you take the mean of two percentages for one category in a table?
Only if the two groups are the same size
Adjusting for the population is . . .
Normalization
Can you add two raw numbers from two different groups for the same category in a table?
Yes
How to find total of a cumulative table
Multiply 1 x Variable
2 x Variable
and so on
Y- and x-axes have
Equal units and intervals
Y-axis MUST
Start at zero, with a small exception
X-axis MUST
Go in chronological or number order from left to right
Gridlines on a chart
Suggest numbers for each column
If there are numbers on each column for a column chart . . .
Gridlines and y-axis could be removed, but the y-axis is implied
Exemption for starting a chart at 0
- When starting at 0 is meaningless, for example, climate change in Fahrenheit
- The changes would be so slight if they started at 0
Never trust a chart with . . .
Two y-axes
An easily misinterpreted chart may have a y-axis that . . .
Starts with 0 at the top
Pie charts should have
- Raw numbers or percentages
- Sizes that vary considerably
- One dominant slice
- An order from largest to smallest clockwise
- Always be 2D
Cumulative charts are misleading if . . .
Used to hide variance
Dimensions
- Always multiplied, length and width
- So if it doubles in height and width, it’s not twice as big, it’s four times as big
Maps often mirror . . .
Population, and do not reflect a apttern
Maps are misused by showing . . .
Geography instead of population
When election results are shaded by state on a map
They aren’t meaningless
When election results are shaded by county on a map
- Becomes misleading because with only 2 colors it looks like the country is mostly one party
- Shading for relative results helps, but does not solve population problem
Problem with any US map is that population . . .
Is concentrated in cities
Using a map to show change
It’s okay because change is normalized for population
Most people think hurricane cone represents . . .
Size of the storm and area affected
Hurricane cone represents
- Center of the storm, not just the width or size
- A hurricane is larger than it’s center, so if you’re outside the cone, you’re not immune
Cone of probability
An informed guess built from computer models
The probability the hurricane will be inside the cone is . . .
- 67% or 2 in 3 times
- The hurricane will move outside the cone 1 in every 3 times
