Chapter 4
nominal data
- least sophisticates - can count, group, and take a proportion
Charts for Quantitative data
- line charts - box and whisker plots - scatter plots - filled geographical maps
ratio data
- most sophisticated - quantitative data - counted and grouped - differenced between each data point is meaningful - has a meaningful 0
Interval data
- no meaningful 0 - counted and grouped - differences between data are meaningful
standard normal distribution
- normal distribution used for standardizing data -0 for its mean and 1 for standard deviation
example of discrete data
- points in a basketball game
discrete data
- represented by whole numbers
benefit of standardizing data
you don't have to compare wildly different numbers and attempt to eyeball how one observation differs from the other
examples of normal distributions
- SAT scores - heights of newborns
normal distribution
- a type of distribution in which the median, mean, and mode are all equal - half of all observations fall below the mean and the other half fall above the mean
Qualitative Comparison Chart Types
- bar chart - pie chart - stacked bar chart - tree map - heat map
3 most used charts with qualitative data
- bar charts - pie charts - stacked bar chart
ordinal data
- can be counted, categorized, and ranked
continuous data
- can take on any value in a range - height
qualitative date
- categorical data - you can count and group
Word clouds
- count frequency of each word mentioned - the higher the frequency the larger the word
examples of ordinal data
- gold, silver, bronzee, 1-5 scales, letter grades
quantitative data
- interval or ratio data - can bee counted ranked, grouped, mean meadian , and std devation
Exploratory visualization
- the lines between performing a test plan, address and refine results, and communicate results are not clearly divided - performing test plan directly in Tableau - answers to the questions from step I won't have already been answered before working with the data in the visualization software
tree and heat maps
- use size and color to show proportional size of values - tree maps show proportions using physical space - heat maps use color to highlight the scale of values
Determining the method for communicating your results required the answers to what two questions?
1) Are you explaining the results of previously done analysis or are you exploring data through visualization 2) What type of data is being visualized
2 Questions that quadrants represent
1) is your purpose declarative or exploratory 2) What type of information is being visualized
Two ways to further define qualitative data
1) nominal data 2) ordinal data
The Fahrenheit scale of temperature measurement would best be described as an example of: A: Interval data B: Discrete data C: Nominal data D: Continuous data
A: Interval data
_________________ data would be considered the most sophisticated type of data A: Ratio B: Interval C: Ordinal D: Nominal
A: Ratio
What is the most appropriate chart when showing a relationship between two variables (according to exhibit 4-8)? A: Scatter chart B: Bar Chart C: Pie graph D: Histogram
A: Scatter chart
Gold, silver, and bronze medals would be examples of: A: Nominal data B: Ordinal Data C: Structured data D: Test data
B: Ordinal Data
Line charts are not recommended for what type of data? A: Normalized data B: Qualitative data C: Continuous data D: Trend lines
B: Qualitative data
Which of the follow IS NOT a typical example of nominal data? A: Gender B: SAT scores C: Hair color D: Ethnic group
B: SAT scores
Justin Zobel suggests that revising your writing requires you to "be egoless-ready to dislike anything you have previously written," suggesting that it is ____________ you need to please A: Yourself B: The reader C: The customer D: Your boss
B: The reader
__________________ data would be considered the least sophisticated type of data A: Ratio B: Interval C: Ordinal D: Nominal
D: Nominal
Exhibit 4-8 gives chart suggestions for what data you'd like to portray. Those options include except: A: Relationship B: Comparison C: Distribution D: Normalization
D: Normalization
If you data project is more declarative than exploratory, it is more likely that you will perform your data visualization to communicate the results
Excel
Why are bar charts more easily interpreted?
Our eyeballs are more skilled at comparing the height of columns than slices of a pie
pie chart
a chart that shows the relationship of a part to a whole
what does the meaningful 0 allow us to do?
calculate fractions, proportions, percentages
proportion
calculated by counting the number of items in a category then dividing that number by the total number of observations
examples of nominal data
color, gender, ethnic group
example of ratio data
currency
Why can qualitative data (nominal and ordinal) be called conceptual data?
data is text driven and represents concepts instead of numbers
Quantitative data can be further categorized as
discrete or continuous
example of interval data
fahrenheit temp scale
symbol maps
geographic maps used to express qualitative data proportions across areas such as states or countries
In all quantitative data the ___________ between data are meaningful
intervals
Why is tableau better for exploratory data analysis
intuitive and easy to use
What is the primary statistic used with quantitative data?
proportion
line charts
show trends over time
bar chart
shows the proportions of each category compared to the others
standardization
the method used for comparing two datasets that follow the normal distribution - standardize with z-scores
declarative visualizations
the product of wanting to declare or present your findings to an audience
excels biggest advantage over Tableau
ubiquity
scatter plots
useful for identifying correlation between two variables or for identifying a trend line or line of best fit
box and whisker plot
useful for when quartiles, median, and outliers are required for analysis and insights - used to detect outliers